Patent ID: 6143679
Filing Date: 2000-11-07
Classification: C30B

Abstract:
A layered crystal structure oxide comprising bismuth (Bi), oxygen (O), a first element Me comprising at least one element selected from the group consisting of sodium (Na), potassium (K), calcium (Ca), barium (Ba), strontium (Sr), lead (Pb) and bismuth (Bi), and a second element R comprising at least one element selected from the group consisting of iron (Fe), titanium (Ti), vanadium (V), niobium (Nb), tantalum (Ta), tungsten (W) and copper (Cu), wherein the crystal structure oxide having a stoichiometric composition of (Bi.sub.2 O.sub.2).sup.2+ Me.sub.m-1 R.sub.m O.sub.3m+1).sup.2-, wherein m is any integer from 2, 3, 4 and 5, wherein the crystal structure having a property selected from the group of properties consisting of at least a part of the bismuth being substituted by one of the other elements constituting the layered crystal structure oxide being substituted; at least a part of at least one element constituting the layered crystal structure oxide being deficient or disordered; and a cation and an anion in a fluorite layer of the crystal structure being relatively displaced by at least 3% of a unit lattice length in a polarization axis direction.