Note: Descriptions are shown in the official language in which they were submitted.
CA 02455428 2004-03-19
PRODUCTION OF CATIONICALLY HOMOGENEOUS
REFRACTORY OXIDES OF NANOMETER-SCALE PARTICLE SIZE
DIAMETERS AT REDUCED TEMPERATURES
Background of the Invention
This invention relates to a generic and novel process,
hereinafter called the Uniform Cation Distribution Process
(UCDP), for producing, at reduced temperatures, cationically
homogeneous nanostructured refractory metal hydroxyhalides,
metal oxyhalides and metal oxides and to the novel products
thereof.
More particularly, this invention relates to a process
for the manufacture, from small to commercial size quanti-
ties, of refractory oxides of all compositional categories
including undoped, doped, solid solution, congruent melting,
incongruent melting, stoichiometric and non-stoichiometric
compositions as polycrystalline, glass or three-dimensional
single crystalline entities, by thermochemical reactions of
hydrated homogeneously dispersed colloidal mixtures of
halides or halide-oxides which form and decompose as pre-
cursor complexes into refractory oxide end products.
Prior art halide hydrolysis practiced consisted of
vapor phased hydrolysis, as exemplified by the below
references, or by crystallizing small, thin, stoichiometric,
binary oxide single crystals from programmed temperature-
cooled solutions. The purity and quality of the resultant
crystals were poor mainly because of inevitable solvent
inclusions in the crystals and the very low acceptable
crystal yields were seldom reproducible due to insufficient
hydration for complete thermochemical hydrolysis of metal
halides.
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Some references describing thermohydrolytic prior art
procedures for synthesizing refractory oxide compounds, are:
1. Popov, A.I.; Knudson, G.E., "Preparation and Properties
of the Rare Earth Fluorides and Oxyfluorides,"J. Am.
Chem. Soc., 76, Feb. 1954, p. 3921.
2. Brixner, L.H., "Ferromagnetic Material Produced From
Ferric Oxide And Barium Halide or Strontium Halide, And
Process For Making Same," U.S. Patent 3,113,109, Dec.
3, 1963.
3. Messier, D.R.; Pask, J.A., "Kinetics of High Temper
ature Hydrolysis of Magnesium Fluoride: II, Influence
of Specimen Geometry and Type and of Product Layers",
J. Am. Cer. Soc., Vol 48, No. 8, Sept. 1965, p. 459.
4. bugger. C.O., "The Growth of Pink Magnesium Aluminate
(MgA1209) Single Crystals," J. of Electrochem. Soc., Vol
113, No. 3, March 1966, p. 306.
5. bugger, C.O., "Solution Growth of Oxidic Spinet and
Other Oxide Single Crystals Following The Hydrolysis of
Some Fluorides," J. of Phys. & Chem. of Solids
Supplement, 1st Ed., Pergamon Press, New York, 1967, p.
493.
6. bugger, C.O., "Method For Growing Oxide Single Crys-
tals," U.S. Patent 3,595,803, July 27, 1971.
7. Utsunomya, T.; Hoshino, Y.; Sato, M., "Process of Hy-
drolysis Reaction from YF3 to Y203 in a Humid Air at
High Temperatures," Bulletin of the Tokyo Institute of
Technology, No. 108, 1972.
Brixner, U. S. Patent No. 3,113,109, discloses a process for
the production of a ferromagnetic refractory oxide material
from ferric oxide and barium halide or strontium halide, in
the presence of water vapor, oxygen or a mixture thereof, at
700-1350°C. In one aspect, a molten mixture of the ferric
oxide and a 2-3 times stoichiometric excess of the metal ha-
lide is employed as the reaction medium. In such a
technique, the cation composition of the molten mixture
differs from that of the oxide product, i.e., the molar ratio
2
CA 02455428 2004-03-19
of the metal halide is greater in the reaction medium than
its molar ratio in the refractory oxide product. Even though
the product is in the form of single crystals, the product
inherently is not ca n onically homogeneous because of
S occluded canons from the reaction medium. Also, although
transparent single crystals were obtained, they were in the
form of thin substantially two dimensional platelets (10-100
microns thick and up to 2 mm in diameter); unlike three-
dimensional single crystals of this invention.
The UCDP differs from the prior art refractory oxide
manufacturing processes in that the refractory oxides are
prOduCed r .,r r~_ r r _fr~m ~ Cat10n1Call ~~ hnmngenen»c nappstrtlCttlred
substantially pure oxyhalides. The UCDP also differs in that
it can produce on both large and small scales, a wide variety
of novel and known crystalline refractory oxides of all
compositional categories from the three states of matter
[solid, liquid (molten) and vapor states).
While the UCDP is a generic process for producing pre
cisely high reproducible yields of all of the refractory
oxide compositional categories, there is some scientific
uncertainty as to the actual precursor (intermediate) reac-
tions that occur in thermochemically converting a hydrated
metal halide to a refractory oxide end product; hydroxyhalide
and oxyhalide complexes are reported in the literature. In
addition, it is not certain if all hydrated metal halides
convert to both intermediate complexes. In this invention,
however, it is assumed that all hydrated metal halides are
thermochemically converted to both hydroxyhalide and
oxyhalide complexes only, and the hydroxyhalide and the oxy-
halide complexes are considered to be low temperature
500°C) and high temperature complexes, respectively. A
chemical complex composition of this invention consists of
3
CA 02455428 2004-03-19
one or more metal halides bonded to oxygen, hydroxyl groups
or both. Thus, hydroxyhalides and oxyhalides are chemical
complexes which may exhibit an overall excess electric
charge(s).
In the context of this invention, the term "hydrolysis"
as used herein is the chemical reaction of a substance with
liquid water or its ions.
The use of liquid water as a reactant is a substantial
improvement over the prior art technique of using indetermi
nate moist gases or waters of crystallization as the water
source reactant . The halides used in the UCDP are not only
fully hydrated, ~.ahich ensures complete hydrolytic reactions,
but also the liquid water, of appropriate pH, is a
homogeneous reactant-mixing medium. The combined simul-
taneous chemical exothermic halide-hydration reaction and
homogeneous physical water-mixing produces a homogeneously
dispersed colloidal reactant mixture from which all the UCDP
precursors and refractory oxides are produced.
The term "refractory oxide" is used herein in its
conventional sense. It is a metal oxide, usually of one or
more metal rations and which has a fusion point, i.e., it
becomes molten upon heating. In this invention, the Chemical
Periodic Table metals of Groups IA - VA, IB - VIIB and VIII,
the lanthanides, and the actinides, thorium and uranium can
be used to produce metal halides and oxides. A ration is a
positively charged ion.
The term "canonically homogeneous" means that the re-
fractory oxide is substantially free of occluded extraneous
rations.
A refractory oxide is called either a nanostructured or
nanophased composition when its colloidal particle size dia-
meters are less than about a hundred nanometers. These nano-
4
CA 02455428 2004-03-19
phased materials can be used to produce new classes of ceram
ics and ceramic composites which demonstrate enhanced magnet
ic, electronic and mechanical properties and can lead to ad
vanced materials, engineering breakthroughs and new techno
logies.
The term "substantially pure" as used herein means the
actual cationic composition thereof differs by no more than
about 5 wt~ from theoretical based upon chemical analysis,
preferably less than 2 wto, and most preferably, e.g., in the
case of refractory oxides to be used in a laser or a super-
conductor, 0.25 wto or less.
Objects of the Invention
A primary object of this invention is to provide a
novel, generic and highly reliable process which, on a com
mercial scale, can produce refractory oxides that are
can onically homogeneous, nanostructured and substantially
pure.
Another object is the provision of a process for the
manufacture of such refractory oxides at temperatures ranging
from 100°C to 1500°C below their pure melting points.
Yet another object is the manufacture of novel refrac-
tory oxide compositions.
A further object of this invention is to provide a pro
cess which markedly reduces or eliminates the prior art dis
advantages attendant to refractory oxide materials prepara
tion.
Still further objects of advantages and features of
this invention will become apparent upon consideration of the
following detailed description thereof.
5
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Summary of the Invention
In a process aspect, this invention relates to a pro-
cess which comprises producing a ca n onically homogeneous
nanostructured substantially pure metal oxyhalide which is
thermochemically decomposes, by heat alone, into its refrac-
tory oxide.
In a preferred process aspect, this invention relates
to a generic process for producing a refractory oxide which
comprises (a) reacting and dispersal-blending liquid water
with at least one metal oxide reactant and a hydrogen halide
composition to produce a ca n onically-homogeneous nano-
structured colloidal mixture; (b) heating the colloidal
mixture to produce a solid state metal hydroxyhalide; (c)
further heating the metal hydroxyhalide to a higher tem-
perature at which it chemically decomposes, by heat alone,
into a ca n onically-homogeneous nanostructured solid state
metal oxyhalide; and performing one of the following heating
steps: (i) heating the metal oxyhalide to a solid state de-
composition-temperature at which it chemically decomposes, by
heat alone, into a cationically-homogeneous nanostructured
solid state refractory oxide; (ii) heating the metal oxy-
halide to a molten state decomposition-temperature at which
it chemically decomposes, by heat alone, into a cationically-
homogeneous nanostructured solid state refractory oxide;
(iii) heating the metal oxyhalide to a vapor state decomposi-
tion-temperature at which it chemically decomposes, by heat
alone, into a cationically-homogeneous nanostructured solid
state refractory oxide.
In a compositional aspect, this invention relates to
can onically homogeneous nanostructured refractory oxides,
6
CA 02455428 2004-03-19
most of which are transparent and many of which have one or
both of electrostatic and magnetic properties.
In another compositional aspect, this invention relates
to chemically novel refractory oxides.
In yet another compositional aspect, this invention re-
lates to the hydroxyhalide and oxyhalide precursors of the
refractory oxides of this invention.
Detailed Description of the Invention
The UCDP is an extraordinary and powerful manufacturing
process because of its generic capability to manufacture vir-
tually any refractory oxide that can be produced at
atmospheric pressure. Additionally, UCDP's novel products'
properties enable the products to be used in all refractory
oxide procedures and applications such as sensors, filters,
photonics, wave-guides, high strength near-net-shape
structures, superconductors, insulators, catalysts, films,
fibers nuclear waste management, etc.
As illustrated in the examples below, the number of
different cations and their concentrations in the end
products can vary widely. The purity, quality and homo
geneity of the end products are very high and precisely
reproducible.
In a preferred aspect, the refractory oxides of this
invention are produced from a metal oxyhalide precursor
thereto selected from the group consisting of:
a) Bal-~p+s+o.sXJRo.s~PDsUXMgi-yDyAllo-cZ+w~JZQo.~sw~m-o.sgGg
DS=Ca, Sr, Pb; G=F, Cl; Q=Si, Ge;
J=Cr, Ga, Ti, Mn, V, Fe, Co; U=Na, K;
Dy=Co, Cu, Ge, Ni, Zn; R=Y, lanthanides;
g~33.7; 0<_p<_0.6; O~s<_1.0;
0<-x1.2; 0-<y<_l; O~z~0.6; O~w<7.5;
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b ) Baz-pNal-(x> KxRo. 6~PNbs-yTayOls-o. sgGg
G = F, Cl; R = Y, Lanthanides
gS29.7; O~p~0.6; O~x~l.0; 0<_y<_5.0;
C) Sr1-(x+2p+z)BaxUpRp-Jp,n7zNb2-yTay~6-O.SgGg
G = F, C1; U = Na, K;
J = Cr, Fe; R = Y, Lanthanides;
g~1.7; O~p~0.18; O~X<_1; 0<_y<_2; O~z~0.18;
d) Bal_xDXTii-(y+o.;sZ)Jz~ry03-o.sgGg
D = Sr, Pb, Ca;
G = F, Cl; J = Fe, Cr
g~5.7; O~x~l; 0<_Y_1; O~z~0.1;
e) KTai-cx+o.6yNbxJvO3-0.5gGg
G = F, C1; J = Cr, Fe;
g<5.7; 0<x<1; 0<y<0.1;
Ll~-(x+z+d) D0. SxD0.5dJ0.33zTa1-yNbyO3-O. SgGg
Dx = Ni, Co, Fe, Mg; G = F, C1;
Dd= Ni, Co, Cu, Zn; J = Cr, Fe; G = F, C1
05d~0.12; g~5.7; O~x~l; O~y~l; O~z~0.4;
g) Mgi-cx+y+z) DzJo. b~yRo.6~xOi-o. sgGg
D = Ni, Co, Fe, Cu, Ge, Zn;
J = Cr, Fe, Ti; G = F, C1; R = Lanthanides
C~~1 . 7 ; D~XCO . 015; V ~y~l; U~Z~1;
h) Mgl-zDzAl2-tx+v)RxJy~4-o.sgGg
G = F, Cl; D = Co, Ni, Cu, Zn, Ge
J = Co, Cr, Fe, Mn, Ti, V; R = Lanthanides
g<7.7; 0<x~l; 0<y~2; 0<z51;
i) Pb2-zDZKl-x)NaxNbs-vTayOls-o.sgGg
DZ = Ba, Ca; G = F, Cl;
g<29.7; 0<-x<_1, O~y~S, O~z~2;
) Y2- (x+dl RxJa03-o. sgGg
G = F, C1; R = Lanthanides;
J = Cr, Ga, Ti, Fe, A1, V, Co, Ni, Cu, Mn;
O~d~0.15; g<-5.7; O~x~2;
k ) A12- (x+v+w> RxJvQo. ~sw03-o. sgGg
J = Cr, Ga, Ti, Fe, V, Co, Mn;
G=F, C1; Q= Si, Ge, Sn; R = Lanthanides;
g~5.7; O~x~0.12; O~y~0.12; O~w<_1.8;
8
CA 02455428 2004-03-19
1 ) Y3-xRxAlS- (y+w) JyQO. 75w012-0. SgGg
G = F, C1; R = Lanthanides
J = Cr, Ga, Ti, Fe, V, Co, Mn;
Q = Si, Ge
g_<23.7; O~w<_5; O~x<3; 0-<<y~0.5;
m) Y3-xRxFeS_yJyO~2-O.sgGg
G = F, C1; R = Lanthanides
J = Cr, Al, Ga, Co, Mn;
g<_23.7; 05x<-3; 0<-y<-5; and
where "U" "D" "R" "J" and "Q" are one or more: uni-
valent, divalent, rare-earth, trivalent and tetravalent
ca n ons, respectively; and, "G" is one or more halogen ions;
and, each lower-case letter of the formulae denotes a
variable numerical value of the atomic ratio of that chemical
element in the composition. The preferred refractory oxides
of this invention otherwise correspond to the above formulae
without the Gg element.
UCDP compositions are manufactured by the below thermo
chemical Reactions I-IV. For example, in the case of yttrium
oxide (Y203), the overall reaction equation is:
30
2YF3 (p) + 3H20 (1) --> Yz03 (c) + 6HF (g)
The hydrogen fluoride product weight percent loss is ca. 350.
Reaction I: YF3 hydration (chemisorption ca.20°C to ca.
150°C)
2YF3(p) + 3H20(1) --> 2[YF3~1.5H20] (c) + heat.
Reactio:. II: Thermochemical halide hydrolytic reactions
and shifting chemical equilibria cause the
formation of a solid state hydroxyfluoride
complex from ca. 150°C to ca. 500°C.
2 [YF3~1 .5H20] (c) --> YZ (OH) 3F3 (c) + 3HF (g)
Reaction IIA: Oxide-hydrogen halide hydrolytic group alter-
nate reaction to Reactions I & II.
9
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Y203 + 3HF --> Y2 (OH) 3F3
Reaction III: Increasing temperature (>500°C), shifting
chemical equilibria and solid state activated
hydroxyfluoride decomposition causes the for-
mation of a solid state oxyfluoride complex
at ca . 1000°C .
YZ (OH) 3F3 (C) --> Y2~3F33 (c) + 3H+(g)
Reaction IIIA: Solid state activated oxyhalide complex
decomposition to refractory end product at
ca. 1100°C & 80 hrs.
Y2~3F33 ( C ) --> Y2O3 ( C ) ~- 3 F ( g )
Reaction IV: Molten or vapor state isothermal y~O~F33-(~i,g)
decomposition temperature at ca. 1550°C pro-
duces transparent Y203 crystals.
YzO3F33 (m, g) to fcrm YZO3 (c) + 3F (g)
In the above equations, p=powder; 1=liquid; g=gas; c=crys-
talline; m=molten; and --> = reaction direction and heating.
The proposed Reactions I-IV are assumed to be molecular
complex reactions that proceed by shifting ehemic:al equi-
libria irreversibly to the right to produce refractory
oxides.
A general implementation of the above UCDP manufactur-
ing thermochemical reactions is as follows:
1. Write the appropriate chemical equations and calculate:
a) reactant weights;
b) product weight percent loss..
2. Use at least one metal oxide and a hydrogen halide com-
position. Calculate and weigh out each reactant; se-
quentially, homogeneously dry-mix the reactants, mix
with water to form a homogeneously dispersed colloidal
state, dry the uniform mixture up to about 150°C and
pulverize and sieve the mixture through a 200 mesh
screen (Reaction I).
CA 02455428 2004-03-19
3. Place the powdered composition in a pre-weighed empty
crucible, weigh and program heat the crucible to the
appropriate temperature and hold for an appropriate
time which ensures complete solid state hydroxyhalide
complex formation (Reaction II).
4. Cool the furnace; weigh the crucible and determine the
composition's wto loss; pulverize the composition and
sieve through 200 mesh screen. Use X-ray analysis to
confirm that the precursor complex phase has completely
formed.
5. Compact and place the powdered composition in a pre-
weighed empty crucible, weigh and program heat the cru-
cible to a Reaction III temperature and maintain the
contents at that temperature for a period of time suf
ficient to ensure the oxyhalide reaction has gone to
completion. Determine wt o loss, pulverize, sieve and
X-ray to confirm that the presence of the precursor
complex phase.
6 Compact the Step 5 composition and program heat it to a
Reaction IIIA temperature. Maintain a constant
(isothermal) temperature for a sufficient time period
to ensure the decomposition of the solid state
activated oxyhalide complex.
7. Compact the Step 5 composition and program heat it to a
ReaCtiOii i vJ mvi teii t2mperatiir2 .
8. Program cool the molten temperature to a lower molten
or solidification temperature; or, isothermally
maintain or program cool an end product seed crystal in
contact with the molten complex.
9. Heat the compacted composition from Step 5 to within a
temperature range from about twenty (20°C) Celsius de
grees to three hundred (300°C) Celsius degrees above the
Reaction IV initial molten temperature to obtain a
vapor state temperature.
10. Obtain a refractory oxide end product compound by: a)
maintaining, isothermally, the higher Step 9 temper-
ature for a sufficient time period to ensure that the
shifting chemical equilibria caused by the gas-forming
reactions and the consuming decomposition reactions of
the vapor state activated complexes to solid oxide are
completed.
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CA 02455428 2004-03-19
11. Perform X-ray, chemical and infrared absorption
analyses on the end product composition.
12. Anneal, if necessary to impart a specific property to
the refractory oxide, in an appropriate gaseous envi-
ronment, such as dry or moist air, O2, H2, Nz, CO/COz,
HF, He or Ar.
The temperatures at which the Reactions I-IV occur in
the process of this invention range from about ambient (20°C)
temperature for the initial reaction to about 1700°C for the
final refractory oxide production step and at virtually any
pressure which does not adversely affect shifting chemical
equilibria reactions. The length of time for a complex to
decompose is principally a function of the complex composi-
tion, the quantity of the complex and the decomposition
temperature employed. The reaction time periods are usually
maintained for a plurality of hours at designated
temperatures to ensure that a complete complex reaction is
achieved. These reaction parameters can be empirically esti-
mated and roughly in situ determined. More sophisticated
known in situ thermoanalytical techniques can be used to de-
termine the optimum UCDP reaction kinetic parameters, which
can then be precisely reproduced.
The specific decomposition-temperatures used depend
upon the specific oxyhalide being thermochemically decomposed
but generally is about 100°C to 1500°C below the true melting
point of the corresponding refractory oxide. Ordinarily the
temperatures are maintained substantially constant, e.g.,
within about 5°C and preferably within about 1°C. The ge
neric process of this invention, therefore, provides a
precise, highly reproducible yield process for manufacturing
all refractory oxide compositional categories at lower tem-
peratures than heretofore possible and produces refractory
oxide end products which are cationically homogeneous, with
12
CA 02455428 2004-03-19
manometer-scale particle sizes, of high quality and purity as
verified by chemical and/or X-ray analyses. The invention
also provides a method for the manufacture not only of
refractory oxide compositions which are presently commer-
d ally available but also heretofore commercially unavailable
known refractory oxides. The process also enables the manu-
facture of a potentially inexhaustible number of novel
refractory compositions, including those disclosed herein.
In the manufacture of refractory oxides by the UCPD,
fluorides, chlorides and fluoride-chloride combinations are
used. Also additional reactants may be used, such as other
halides, hydroxides, carbonates, nitrates and sulfates;
whether anhydrous or hydrated. Although ultrapure pure
reactants may be used to produce refractory oxides of the
highest of purity, off-the-shelf (reagent grade) chemical re-
actants generally are used because they become highly
purified during the complex formation-decomposition reac-
tions. Thus, UCDP refractory oxide end products can be
manufactured very economically.
In the UCDP's chemical vapor deposition procedure,
chlorides are generally used rather than fluorides because
chlorides melt at much lower temperatures and exhibit much
higher vapor pressures at given temperature than fluorides.
Each example below exhibits a decomposition-temperature
range derived by heating a small sample reactant mixture to
each of the temperatures at which a chemical conversion
occurs and maintaining the sample at each of those temper
atures for at least about three hours. Microscopic exami
nations of the compositions can identify the molten state
ranges.
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A variety of furnaces and techniques can be used to
manufacture refractory oxide compositions by the UCDP from
solid, molten, or vapor states. The furnace-pressure capa-
bilities can range from negative pressures (vacuums) to
overpressures greater than one atmosphere. Compacted
reactant-mixture billets or platinum, ceramic or molybdenum
crucibles can be used to hold the reacting compositions in
the appropriate gas environments such as air, nitrogen,
oxygen and hydrogen.
Each example below is either a specific representative
derivative compound of the parent compound or a specific par-
ent compound selected for manufacture from the immediate
below general formula group series. Each group is of similar
chemical-type of compounds, within given concentration range
and suggests similar UCDP temperature-range manufacture. No
new X-ray lattice constants were determined for doped and
solid solution compounds if a JCPD X-ray card does not exist.
The lattice constants of these compounds are reported as the
standard JCPD values for identical constituent compounds but
of different concentrations. In general, a parent compound
is one in which the elements' atomic ratios (subscript
numbers) are integers.
In the examples, air at atmospheric pressure, was the
furnace gas environment used; and, lanthanides are the atomic
number elements 57 to 71 of the Chemical Periodic Table.
GENERAL FORMULA GROUP SERIES
The novel refractory oxides described below are pro
duced from a metal oxyhalide precursor, whose structure
otherwise corresponds thereto except for the absence of the
Gg element, selected from the group consisting of:
14
CA 02455428 2004-03-19
1 ) Bal-(2p+s+0. sx) UpRpDSAxMgl-yDyAllo- (Z+w) JZQo.
~sw~m
2 ) Ba2-apNal- (x-p) KxRpNbs-yTayOis
3 ) S rl- (x+2p) BaxUpRpJO. 57Nb2_yTay~g
4 ) Bal-xDXTil_ (y+o.~sZ) Jzzry03
5) KTal-(x+o.6y)NbxJy03
L11-(x+z+d) D0.5xD0.5dJ0.33zTa1-yNby~3
7 ) Mgl-(x+y+z) DzJo.6'7yRo.67x~
8 ) Mg1-xDXAl2-yJy09
9 ) Pb2-ZDZKi-xNaxNbs-yTayOls
10 ) YZ-xRXJd03
11 ) Pal2- (x+y+w) RxJyQ0.75w~3
12 ) Y3-xRxAls (y+w) JyQo.75w~12
13 ) Y3-xRxFes-yJy012
#here "U", "D", "R", "J" and "Q" are as defined hereinabove.
The UCDP manufacturing procedure, which illustrates
Reactions I-IV, as already set forth, is responsible for
the
production of an assortment of compositions. The below
examples a re given to exemplify the UCDP and the scope of
the
invention and are not intended to be limiting in the sense
of
the scope of the invention.
EXAMPLE I
General Formula
Bal_(p+S+o.sx)Ro.67pDsUxMgi-yDyAllo-(Z+w)JzQo.7swW 7
R=Y, lanthanides; DS=Ca, Sr, Pb; U=K, Na;
Dy=Co, Cu, Ge, Ni, Zn; J=Cr, Ga, Ti, Mn, V, Fe, Co;
Q=Si, Ge;
0<_p<_0.6; 0.05SsS1; O~w<_7.5;
0<_x<_1.2; 0<-y<-1; 0<-z<_0.6
Specific End Product Compound
Bao.9oNao.osNdo.osMg~119.siaCro.oo6Tio.oaCm (c)
(New Composition)
The temperature of a three gram reactant mixture, con-
sisting of, in mole %, 3.12BaFz + 0.02NaF + 0.02NdF3 + 3.5MgFz
CA 02455428 2004-03-19
+ 20.6A1F3 + 6.9AIz03 + O.O1Ti203 + 58.5HZ0, in an alumina
crucible, was raised to the isothermal decomposition-temper-
ature of 1370°C for five (5) hours. The temperature was then
programmed cooled at 15°C per hour to 1175°C and the furnace
cooled to room temperature. The ca non reactant concentra-
tions were: A1=82.6 at.o, Mg=8.3 at.%, Ba=7.5 at.o, Ti=0.7
ato, Na=0.4 at. o, Nd=0.4 at. a, Cr=0.1 at. o. The X-ray purity
is 990. The crystal class is hexagonal where a=5.625A and
c=22.62A. After materials characterization, the compound is
then ready for potential fabrications and applications, such
as a solid state electrolyte, phosphor, red or tunable laser.
EXAMPLE II
General Formula
20
L11-(x+z+d) D0.5xD0.5dJ0.33zTa1-yNbyO3
Dx = Ni, Co, Fe, Mg; Dd= Ni, Co, Cu, Zn;
J = Cr, Fe; G = F, Cl;
0<_d<_0.12; 0<-x<-1; 0<-y~l; O~z-0.4
Specific End Product Compound
LlTap.65Nb0.3503 (C)
The temperature of a three gram reactant mixture, con-
sisting of, in mole%, 50LiF + 8.8Nb205 + 16.3Ta205 + 25H20, in
an alumina crucible, was raised to the isothermal decomposi-
tion-temperature of 1160°C for five (5) hours. The tempe-
rature was then programmed cooled at 20°C per hour to 1000°C
and the furnace cooled to room temperature. The crystal
structure is rhombohedral with a=5.1539A and c=13.81512A.
After materials characterization, the compound is then ready
for potential electro-mechanical transduction fabrications
and applications.
EXAMPLE III
General Formula
Mgi- (x+y+Z) DZJo. 6~yRo. s~x0
D = Ni, Co, Fe, Cu, Ge, Zn;
J = Cr, Fe, Ti; R = Lanthanides
0<-x<-0.005; 0-<y<-1; 0<_z<_1
Specific End Product Compound
Mg0(c)
The temperature of a three gram reactant mixture, con-
sisting of in mole o, 50MgF2 + 50H20, in a magnesium oxide
16
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crucible, was raised to the isothermal decomposition-tempera-
ture of 1290°C for eight (8) hours. The temperature was then
programmed cooled at 20°C per hour to 1050°C and the furnace
cooled to room temperature. The cation reactant concentrat-
ions was: Mg=100 at.%. The X-ray purity is 1000. The crystal
class is cubic with a=4.213A. The product is suitable for
use in infrared transmission and substrate fabrications and
applications.
EXAMPLE IV
General Formula
Pb2_ZDZKl_XNaxNbs-yTayOls
DZ = Ba, Ca;
0<_x_<1; 0<_y_<5; 0_<z<_2
Specific End Product Compound
Pb2KNbsOls ( c )
The temperature of a three gram reactant mixture; con-
sisting of, in mole o, 25PbF2 + 12 . 5KF + 31. 3Nb20s + 31 . 3H20,
in an alumina crucible, was raised to the isothermal decompo-
sition-temperature of 1120°C for five (5) hours. The
temperature was then programmed cooled at 10°C per hour to
1070°C and the furnace cooled to room temperature. The cat-
ion reactant concentrations were: Pb=25.0 at.%, K=12.5 at.%,
Nb=62.5 at.~. The crystal class is orthorhombic with
a=17.757A, b=18.O11A, c=3.917A. The product can be used in
ferroelectric-ferroelastic fabrications and applications.
EXAMPLE V
General Formula
Y3_XRXAls_ ~y+W~ JyQo.7sW012
J = Cr, Ga, Ti, Fe, V, Co, Mn;
Q = Si, Ge; R = Lanthanides
0<_x<_3; 0<_y_<0.5; 0<-w-<5;
Specific End Product Compound
Y2.71Nd0.29A14.999Cr0.006~12 (C)
The temperature of a three gram reactant mixture, con-
sisting of in mole o of, 13 . 6YF3 + 1. 5NdF3 + 14 . 9A1F3 + 5A120s
+ 60H20 + 150ppm Cr203, in an alumina crucible, was raised to
17
CA 02455428 2004-03-19
the isothermal decomposition-temperature of 1430°C for six
(5) hours. The temperature was then programmed cooled at
15°C per hour to 1150°C and the furnace cooled to room tem-
perature. The cation reactant concentrations were: Y=33.87
at.%, Nd=3.63 at.~, A1=62.42 at.$, Cr=0.08 at.$. The X-ray
purity is 99%. The crystal class is cubic where a=12.009.x.
The product is suitable for use in doubly doped laser fabri-
cations.
While the embodiments described herein are illustrative
of the principles of this UCDP invention, various modifica-
tions and advantages may be achieved by those skilled in the
art without departing from the scope and the spirit of this
invention; as defined by the following claims.
_ ~ ~
