Provided is a cathode active material that can simultaneously improve the capacity characteristics, output characteristics, and cycling characteristics of a rechargeable battery when used as cathode material for a non-aqueous electrolyte rechargeable battery. After performing nucleation by controlling an aqueous solution for nucleation that includes a metal compound that includes at least a transition metal and an ammonium ion donor so that the pH value becomes 12.0 to 14.0 (nucleation process), nuclei are caused to grow by controlling aqueous solution for particle growth that includes the nuclei so that the pH value is less than in the nucleation process and is 10.5 to 12.0 (particle growth process). When doing this, the reaction atmosphere in the nucleation process and at the beginning of the particle growth process is a non-oxidizing atmosphere, and in the particle growth process, atmosphere control by which the reaction atmosphere is switched from this non-oxidizing atmosphere to an oxidizing atmosphere, and is then switched again to a non-oxidizing atmosphere is performed at least one time. Cathode active material is obtained with the composite hydroxide particles that are obtained by this kind of crystallization reaction as a precursor.

Provided is a cathode active material that can simultaneously improve the capacity characteristics, output characteristics, and cycling characteristics of a rechargeable battery when used as cathode material for a non-aqueous electrolyte rechargeable battery. After performing nucleation by controlling an aqueous solution for nucleation that includes a metal compound that includes at least a transition metal and an ammonium ion donor so that the pH value becomes 12.0 to 14.0 (nucleation process), nuclei are caused to grow by controlling aqueous solution for particle growth that includes the nuclei so that the pH value is less than in the nucleation process and is 10.5 to 12.0 (particle growth process). When doing this, the reaction atmosphere in the nucleation process and at the beginning of the particle growth process is a non-oxidizing atmosphere, and in the particle growth process, atmosphere control by which the reaction atmosphere is switched from this non-oxidizing atmosphere to an oxidizing atmosphere, and is then switched again to a non-oxidizing atmosphere is performed at least one time. Cathode active material is obtained with the composite hydroxide particles that are obtained by this kind of crystallization reaction as a precursor.

An oriented piezoelectric film, wherein a crystal forming the oriented piezoelectric film, is a perovskite type crystal of the general formula of Ba.sub.1-xCa.sub.xTi.sub.1-yZr.sub.yO.sub.3 (0x0.2, and 0y0.2), and the oriented piezoelectric film has (111) orientation according to a pseudocubic crystal notation.

A method for producing a nickel cobalt complex hydroxide includes first crystallization of supplying a solution containing Ni, Co and Mn, a complex ion forming agent and a basic solution separately and simultaneously to one reaction vessel to obtain nickel cobalt complex hydroxide particles, and a second crystallization of, after the first crystallization, further supplying a solution containing nickel, cobalt, and manganese, a solution of a complex ion forming agent, a basic solution, and a solution containing said element M separately and simultaneously to the reaction vessel to crystallize a complex hydroxide particles containing nickel, cobalt, manganese and said element M on the nickel cobalt complex hydroxide particles crystallizing a complex hydroxide particles comprising Ni, Co, Mn and the element M on the nickel cobalt complex hydroxide particles.

A method for producing a nickel cobalt complex hydroxide includes first crystallization of supplying a solution containing Ni, Co and Mn, a complex ion forming agent and a basic solution separately and simultaneously to one reaction vessel to obtain nickel cobalt complex hydroxide particles, and a second crystallization of, after the first crystallization, further supplying a solution containing nickel, cobalt, and manganese, a solution of a complex ion forming agent, a basic solution, and a solution containing said element M separately and simultaneously to the reaction vessel to crystallize a complex hydroxide particles containing nickel, cobalt, manganese and said element M on the nickel cobalt complex hydroxide particles crystallizing a complex hydroxide particles comprising Ni, Co, Mn and the element M on the nickel cobalt complex hydroxide particles.

The present invention relates to: layered iron arsenide (FeAs), which is more particularly layered FeAs, which, unlike the conventional bulk FeAs, has a two-dimensional (2D) crystal structure, has the ability to be easily exfoliated into nanosheets, and has superconductivity; a method of preparing the same; and a FeAs nanosheet exfoliated from the same.

A single crystal multi-element positive electrode material and a preparation method therefor, and a lithium ion battery. The ratio of the length of the longest diagonal line to the length of the shortest diagonal line of the single crystal particles of the single crystal multi-element positive electrode material measured by an SEM is roundness R, and R?1; and D.sub.10, D.sub.50 and D.sub.90 of the single crystal particles of the single crystal multi-element positive electrode material satisfy: K.sub.90=(D.sub.90?D.sub.10)/D.sub.50, and the product of K.sub.90 and R is 1.20-1.40. The single crystal multi-element positive electrode material is more round and regular in morphology, the single crystal particles have uniform size, less agglomeration and less adhesion. The material has the characteristics of high compaction density, good rate capability and excellent cycle performance.

A thermoelectric conversion material according to an embodiment is expressed by the following formula (1):

(M.sup.1.sub.1-xM.sup.2.sub.x).sub.4Si(Te.sub.1-yM.sup.3.sub.y).sub.4 (1) wherein M.sub.1 represents Ta or Nb, M.sup.2 is at least one element selected from a group consisting of elements of groups 4 to 12 in the periodic table, M.sup.3 is at least one element selected from a group consisting of As, Sb, Bi, Sn and Pb, 0x<0.02, 0y<0.02, and M.sup.2 is an element different from M.sup.1 when 0<x.

An alumina substrate on which an AlN layer is formed and that causes less warping, and a substrate material strong enough to withstand normal handling when an AlN crystal is grown upon it, and prevents cracking and fracturing of a grown crystal when stress is applied during growing or cooling. The substrate has a gap and a rare earth element-containing region inside the AlN layer or at the interface between the AlN layer and the alumina substrate. Warping of the AlN layer can be reduced by lattice-mismatch stress being concentrated at the region and releasing of stress by the gap. The region having a concentrating of stress, and the gap having a low mechanical strength, can induce crackings and fracturings. As a result, contamination of crackings and fracturings into the crystal grown on the substrate can be prevented. The region can ensure a level of mechanical strength sufficient for handling.

Provided is a cathode active material that can simultaneously improve the capacity characteristics, output characteristics, and cycling characteristics of a rechargeable battery when used as cathode material for a non-aqueous electrolyte rechargeable battery. After performing nucleation by controlling an aqueous solution for nucleation that includes a metal compound that includes at least a transition metal and an ammonium ion donor so that the pH value becomes 12.0 to 14.0 (nucleation process), nuclei are caused to grow by controlling aqueous solution for particle growth that includes the nuclei so that the pH value is less than in the nucleation process and is 10.5 to 12.0 (particle growth process). When doing this, the reaction atmosphere in the nucleation process and at the beginning of the particle growth process is a non-oxidizing atmosphere, and in the particle growth process, atmosphere control by which the reaction atmosphere is switched from this non-oxidizing atmosphere to an oxidizing atmosphere, and is then switched again to a non-oxidizing atmosphere is performed at least one time. Cathode active material is obtained with the composite hydroxide particles that are obtained by this kind of crystallization reaction as a precursor.