Disclosed herein are perovskite materials and methods of making an use thereof.

[Object] It is an object of the present invention to provide a lithium tantalate single crystal substrate which undergoes only small warpage, is free from cracks and scratches, has better temperature non-dependence characteristics and a larger electromechanical coupling coefficient than a conventional Y-cut LiTaO.sub.3 substrate. [Means to solve the Problems] The lithium tantalate single crystal substrate of the present invention is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36° Y-49° Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.

A Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle, a preparing method and an application as an efficient fuel cell oxygen reduction catalyst are provided. The Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle, includes: three elements of Fe, Pt and Cu; wherein the Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle has a heterogeneous phase structure in which face-centered cubic and face-centered tetragonal coexist; wherein the heterogeneous phase structure is a face-centered tetragonal phase shell and face-centered cubic core with a high crystal plane index; a surface of the polyhedron nanoparticle has 1 to 2 atomic layers of enriched with Pt; a diameter distribution of the nanoparticles is at a range of 4.5 to 14.5 nm, and an average size is 8.4 nm. In the invention, hexadecylamine, iron acetylacetonate, copper acetylacetonate, platinum acetylacetonate, and 1,2-hexadecanediol are uniformly mixed, and oleylamine and oleic acid are added, condensed refluxed at 320-330° C.

Systems, methods, and compositions are disclosed for a Li-substituted layered-tunneled O3/spinel Na(Ni.sub.xFe.sub.yMn.sub.z)O.sub.2 cathode material, Na.sub.0.87Li.sub.0.25Ni.sub.0.4Fe.sub.0.2Mn.sub.0.4O.sub.2+∂ (LS-NFM) for enhanced sodium ion storage and cycling stability. The LS-NFM electrode is prepared by adjusting the stoichiometric ratio of the Na ion over the sum of Li and transition metal ions below 1. The Rietveld refinement of XRD data indicates that the cathode is composed of 94% layered and 6% spinel components. When cycled at a high current density of 100 mA g.sup.−1, LS-NFM cathode exhibited a first-cycle Coulombic efficiency of 88% and reversible discharge capacity of 107 mAh g.sup.−1 after 50 cycles with the capacity retention of 95%.

An anticorrosive, conductive material includes a first oxide having oxygen vacancies and a formula (I): MgTi.sub.2O.sub.5- (I), where .sub. is any number between 0 and 3 optionally including a fractional part denoting the oxygen vacancies; and a second oxide having a formula (II): Ti.sub.aO.sub.b (II), where 1<=a<=20 and 1<=b<=30, optionally including a fractional part, the first and second oxides of formulas (I) and (II) forming a polycrystalline matrix.

A polycrystalline element includes a table formed of polycrystalline diamond. The table includes a first surface; a second surface spaced apart from the first surface; and at least one side extending between the first surface and the second surface. The table also includes a plurality of extensions also formed of polycrystalline diamond, wherein at least one extension of the plurality of extensions extends away from at least one of the first surface and the at least one side. The at least one extension of the plurality of extensions includes a first portion that is polyhedral shaped. Optionally, the polycrystalline diamond of at least one extension of the plurality of extensions is contiguous with the polycrystalline diamond of the table. The polycrystalline element may be used in downhole tools for boring and well drilling, machine tools, and bearings.

A Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle, a preparing method and an application as an efficient fuel cell oxygen reduction catalyst are provided. The Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle, includes: three elements of Fe, Pt and Cu; wherein the Fe.sub.43.4Pt.sub.52.3Cu.sub.4.3 heterogeneous phase structure polyhedron nanoparticle has a heterogeneous phase structure in which face-centered cubic and face-centered tetragonal coexist; wherein the heterogeneous phase structure is a face-centered tetragonal phase shell and face-centered cubic core with a high crystal plane index; a surface of the polyhedron nanoparticle has 1 to 2 atomic layers of enriched with Pt; a diameter distribution of the nanoparticles is at a range of 4.5 to 14.5 nm, and an average size is 8.4 nm. In the invention, hexadecylamine, iron acetylacetonate, copper acetylacetonate, platinum acetylacetonate, and 1,2-hexadecanediol are uniformly mixed, and oleylamine and oleic acid are added, condensed refluxed at 320-330 C.

Nanodiamonds are grown under conditions where diamond-like organic seed molecules do not decompose. This permits engineered growth of fluorescent nanodiamonds wherein a custom designed seed molecule can be incorporated at the center of a nanodiamond. By substituting atoms at particular locations in the seed molecule it is possible to achieve complex multi-atom diamond color centers or even to engineer complete quantum registers. In addition, it is possible to grow ultra-small nanodiamonds, wherein each nanodiamond, no matter how small, can have at least one bright and photostable fluorescent emitter.

A seed crystal is a crystal of zeolite that is to be deposited on a support when producing a zeolite membrane complex that includes the support and a zeolite membrane formed on the support. A volume-cumulative particle size distribution of the seed crystal, measured by a laser diffraction scattering method, has a coefficient of variation of 0.5 or less and a kurtosis of 5 or less. Use of these seed crystals improves the bonding of zeolite crystals when producing the zeolite membrane. As a result, a dense zeolite membrane can be formed.

Methods of determining and controlling the deformability of ceramic materials, as a nonlimiting example, YSZ, particularly through the application of a flash sintering process, and to ceramic materials produced by such methods. Such a method includes providing a nanocrystalline powder of a ceramic material, making a compact of the powder, and subjecting the compact to flash sintering by applying an electric field and thermal energy to the compact.