GRAIN BOUNDARY-FREE TYPE MANGANESE OXIDE-BASED CRYSTAL, ITS PRODUCTION AND MEMORY SWITCHING TYPE MAGNETIC RESISTANCE ELEMENT

摘要

PURPOSE: To obtain a magnetic resistance element showing switching characteristics of resistance by an electric field by forming single crystal, namely, grain boundary-free type crystal, from an oxide containing Mn, La and Sr in a fixed atomic ratio by a floating zone method. CONSTITUTION: This single crystal has the perovskite-type structure of a composition shown by the general formula, La1-x Srx MnO3 ((x) is 0.168-0.178). The single crystal is formed by blending La with Sr and Mn in an oxide or in the form of a compound to be converted into an oxide by heating in the atomic ratio of La to Mn of 0.832-0.822 and Sr to Mn of 0.168-0.178 and in the ratio of the total of the atomic ratio of La and Sr of 1, sintering in an oxygen atmosphere and subjecting the prepared sintered material to crystal growth from a molten state by a floating zone method. The single crystal is capable of controlling the phase change of crystal structure by a magnetic field at 60-350 degree K and retains switching characteristics of resistance by 0-100kOe magnetic field by utilizing hysteresis of structural phase transition, into single crystal.