A nonaqueous electrolyte battery according to one embodiment includes a negative electrode, a positive electrode and a nonaqueous electrolyte. The negative electrode includes a negative electrode active material-containing layer. The negative electrode active material-containing layer contains a negative electrode active material containing an orthorhombic Na-containing niobium titanium composite oxide. The positive electrode includes a positive electrode active material-containing layer. The positive electrode active material-containing layer contains a positive electrode active material. A mass C [g/m.sup.2] of the positive electrode active material per unit area of the positive electrode and a mass A [g/m.sup.2] of the negative electrode active material per unit area of the negative electrode satisfy the formula (1): 0.95≤A/C≤1.5.

An electrode for a secondary battery comprises a current collector; and an active material-containing layer has active materials which comprise titanium-containing composite oxide having an orthorhombic crystal structure and represented by a general formula Li.sub.2+aM1.sub.2−bTi.sub.6−cM2.sub.dO.sub.14+δ; wherein the active material-containing layer has intensity ratio Ia/Ib in an X-ray diffraction pattern of the active material-containing layer, the Ia and the Ib are obtained by powder X-ray diffraction method using Cu-Kα ray, the intensity ratio is within a range of 0.5≤Ia/Ib≤2, the Ia is the strongest intensity of a diffraction peak among diffraction peaks appearing within a range of 42°≤2θ≤44°, and the Ib is the strongest intensity of a diffraction peak among diffraction peaks appearing within a range of 44°<2θ≤48°. (M1 is at least one selected from the group consisting of Sr, Ba, Ca, Mg, Na, Cs, Rb and K, M2 is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Y, Fe, Co, Cr, Mn, Ni and Al a is within a range of 0≤a≤6 b is within a range of 0≤b<2 c is within a range of 0≤c<6 d is within a range of 0≤d<6 δ is within a range of −0.5≤δ≤0.5.)

Provided are an oxide semiconductor excellent in transparency, mobility, and weatherability, etc., and a semiconductor device having the oxide semiconductor, a p-type semiconductor being realizable in the oxide semiconductor. The oxide semiconductor consists of a composite oxide, which has a crystal structure including a pyrochlore structure, containing at least one or more kinds of elements selected from Nb and Ta, and containing Sn element, and its holes become charge carriers by the condition that Sn.sup.4+/(Sn.sup.2++Sn.sup.4+) which is a ratio of Sn.sup.4+ to a total amount of Sn in the composite oxide is 0.124≤Sn.sup.4+/(Sn.sup.2++Sn.sup.4+)≤0.148.

A piezoelectric composition including copper and a complex oxide having a perovskite structure represented by a general formula ABO.sub.3, in which an A site element in the ABO.sub.3 is potassium or potassium and sodium, a B site element in the ABO.sub.3 is niobium or niobium and tantalum, the copper is included in n mol % in terms of a copper element with respect to 1 mol of the complex oxide, and n satisfies 0.100≤n≤1.000.

According to one embodiment, there is provided an active substance. The active substance includes secondary particles and a carbon material phase formed on at least a part of a surface of each of the secondary particles. Each of the secondary particles is constructed by aggregated primary particles of an active material. The primary particles of the active material includes a niobium composite oxide represented by Li.sub.xM.sub.(1−y)Nb.sub.yNb.sub.2O.sub.(7+δ), wherein M is at least one selected from the group consisting of Ti and Zr, and x, y, and δ respectively satisfy 0≦x≦6, 0≦y≦1, and −1≦δ≦1. The secondary particles have a compression fracture strength of 10 MPa or more.

According to one embodiment, an active material is provided. This active material includes active material particles containing orthorhombic Na-containing niobium titanium composite oxide, and satisfies the following formula (1):

1≦A5/A0  (1) where A5 is a mole content ratio of a Li mole content L5 to a total of a Ti mole content T5 and a Nb mole content N5, and A0 is a mole content ratio of a Li mole content L0 to a total of a Ti mole content T0 and a Nb mole content N0.

According to one embodiment, an active material is provided. The active material includes a composite oxide including yttrium atoms in an orthorhombic crystal structure thereof. Also included in the orthorhombic crystal structure of the composite oxide is at least one selected from the group consisting of alkali metal atoms and alkaline earth metal atoms. Among crystal sites represented by Wyckoff notations in the orthorhombic crystal structure, an occupancy of crystal sites that can be occupied by the alkali metal atoms or by the alkaline earth metal atoms is less than 100%.

A lithium ion-conducting compound, having a garnet-like crystal structure, and having the general formula: Li.sub.n[A.sub.(3-a′-a″)A′.sub.(a′)A″.sub.(a″)][B.sub.(2-b′-b″)B′.sub.(b′)B″.sub.(b″)][C′.sub.(c′)C″.sub.(c″)]O.sub.12, where A, A′, A″ stand for a dodecahedral position of the crystal structure, where A stands for La, Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and/or Yb, A′ stands for Ca, Sr and/or Ba, A″ stands for Na and/or K, 0<a′<2 and 0<a″<1, where B, B′, B″ stand for an octahedral position of the crystal structure, where B stands for Zr, Hf and/or Sn, B′ stands for Ta, Nb, Sb and/or Bi, B″ stands for at least one element selected from the group including Te, W and Mo, 0<b′<2 and 0<b″<2, where C and C″ stand for a tetrahedral position of the crystal structure, where C stands for Al and Ga, C″ stands for Si and/or Ge, 0<c′<0.5 and 0<c″<0.4, and where n=7+a′+2.Math.a″−b′−2.Math.b″−3.Math.c′−4.Math.c″ and 5.5<n<6.875.

The invention relates to Eu.sup.2+-activated phosphors, to a process of its preparation, the use of these phosphors in electronic and electro optical devices, such as light emitting diodes (LEDs) and solar cells and especially to illumination units comprising said magnesium alumosilicate-based phosphors.

A bismuth and magnesium co-doped lithium niobate crystal includes Li.sub.2CO.sub.3, Nb.sub.2O.sub.5, Bi.sub.2O.sub.3 and MgO, wherein the molar ratio of [Li] and [Nb] is 0.90-1.00, the molar percentage of Bi.sub.2O.sub.3 in the mixture is 0.25-0.80%, and the molar percentage of MgO in the mixture is 3.0-7.0%. The bismuth and magnesium co-doped lithium niobate crystal has enhanced photorefraction, improved photorefractive sensitivity, shortened holographic grating saturation writing time, and the photorefractive diffraction efficiency can reach up to 17%. The response time is only 170 ms, when the holographic storage experiment is carried out using 488 nm continuous laser. Therefore, this crystal can be used in the field of holographic imaging.