The present disclosure discloses a gradient single-crystal positive electrode material, which has a chemical formula of LiNi.sub.xCo.sub.yA.sub.1-x-yO.sub.2@mLi.sub.aZ.sub.bO.sub.c, wherein 0<x<1, 0<y<1, 0<x+y<1, 0<m<0.05, 0.3<a10, 1b<4, and 1c<15, A is at least one of Mn, Zr, Sr, Ba, W, Ti, Al, Mg, Y, and Nb, and Z is at least one of B, Al, Co, W, Ti, Zr, and Si. The atomic ratio of the content of Co on the surface of the single-crystal positive electrode material particle to the content of Ni+Co+A on the surface is greater than 0.4 and less than 0.8, and the atomic ratio of Co at a depth 10% of the radius from the surface of the single crystal positive electrode material particle is not less than 0.3; and the single-crystal positive electrode material particle has a roundness of greater than 0.4, and is free from sharp corners.

The present disclosure discloses a gradient single-crystal positive electrode material, which has a chemical formula of LiNi.sub.xCo.sub.yA.sub.1-x-yO.sub.2@mLi.sub.aZ.sub.bO.sub.c, wherein 0<x<1, 0<y<1, 0<x+y<1, 0<m<0.05, 0.3<a10, 1b<4, and 1c<15, A is at least one of Mn, Zr, Sr, Ba, W, Ti, Al, Mg, Y, and Nb, and Z is at least one of B, Al, Co, W, Ti, Zr, and Si. The atomic ratio of the content of Co on the surface of the single-crystal positive electrode material particle to the content of Ni+Co+A on the surface is greater than 0.4 and less than 0.8, and the atomic ratio of Co at a depth 10% of the radius from the surface of the single crystal positive electrode material particle is not less than 0.3; and the single-crystal positive electrode material particle has a roundness of greater than 0.4, and is free from sharp corners.

This invention provides a process for increasing the crystallinity of at least one solid material which is less than 100% crystalline, comprising contacting said solid material with solvent in which the solid material is insoluble or poorly soluble (a non-solvent); and applying ultrasound to the solid material when in contact with said non-solvent.

This invention provides a process for increasing the crystallinity of at least one solid material which is less than 100% crystalline, comprising contacting said solid material with solvent in which the solid material is insoluble or poorly soluble (a non-solvent); and applying ultrasound to the solid material when in contact with said non-solvent.

An alumina sintered body according to the present invention has a degree of c-plane orientation of 90% or more as determined by Lotgering's method from an X-ray diffraction profile obtained by irradiating a plate surface with X-rays in a range of 2=20 to 70. The alumina sintered body has no pores when a cross-sectional surface formed in a direction perpendicular to the plate surface is polished using an Ar.sup.+ ion beam and a mask and is examined under a scanning electron microscope at a magnification of 5,000 times. The alumina sintered body has a total mass fraction of impurity elements other than Mg and C of 100 ppm or less. This alumina sintered body has a high degree of orientation, high density, and high purity and thus has a higher optical translucency than those known in the art.

This invention provides a process for increasing the crystallinity of at least one solid material which is less than 100% crystalline, comprising contacting said solid material with solvent in which the solid material is insoluble or poorly soluble (a non-solvent); and applying ultrasound to the solid material when in contact with said non-solvent.

This invention provides a process for increasing the crystallinity of at least one solid material which is less than 100% crystalline, comprising contacting said solid material with solvent in which the solid material is insoluble or poorly soluble (a non-solvent); and applying ultrasound to the solid material when in contact with said non-solvent.

A method for manufacturing a photovoltaic device includes a step of depositing one of an amorphous layer of ZnTe and a multilayer stack of Zn and Te adjacent a semiconductor layer. The one of the amorphous layer and the multilayer stack is then subjected to an energy impulse at a temperature equal to or greater than its critical temperature. The energy impulse results in an explosive crystallization to form a polycrystalline layer of ZnTe from the one of the amorphous layer and the multilayer stack.

The present invention provides: an electrophotographic photosensitive member which reduces image defects due to ghosting not only under a normal temperature and normal humidity environment but also even under a low temperature and low humidity environment; and a novel phthalocyanine crystal. The electrophotographic photosensitive member of the present invention comprises a photosensitive layer which comprises a phthalocyanine crystal in which a N,N-dimethylformamide is contained. The content of the N,N-dimethylformamide is 0.1% by mass or more and 1.5% by mass or less based on the phthalocyanine crystal.

The present invention provides: an electrophotographic photosensitive member which reduces image defects due to ghosting not only under a normal temperature and normal humidity environment but also even under a low temperature and low humidity environment; and a novel phthalocyanine crystal. The electrophotographic photosensitive member of the present invention comprises a photosensitive layer which comprises a phthalocyanine crystal in which a N,N-dimethylformamide is contained. The content of the N,N-dimethylformamide is 0.1% by mass or more and 1.5% by mass or less based on the phthalocyanine crystal.