Localized to Itinerant Electronic Transition in Perovskite Oxides / Edition 1

by John B. Goodenough, S.L. Cooper, T. Egami, J.B. Goodenough, J.-S. Zhou

Overview

Interest in the transition metal oxides with perovskite related structures goes back to the 1950s when the sodium tungsten bronzes NaxWO3 were shown to be metallic [1 ], the system Lal_xSr MnO3 was found to contain a ferromagnetic conductive phase [2], and La0.sSr0.sCoO3 was reported to be a ferromagnetic metal, but with a peculiar magnetization of 1.5 #a/Co atom [3]. Stoichiometric oxide perovskites have the generic formula AMO3 in which the A site is at the center of a simple cubic array of M sites; the oxide ions form (180 ° 4)) M O M bridges to give an MO3 array of corner shared MO6/2 octahedra and the larger A cations have twelvefold oxygen coordination. Mismatch between the A O and M O equilibrium bond lengths introduces internal stresses. A compressive stress on the MO3 array is accommodated by a lowering of the M O M bond angle from 180 ° to (180 ° 4)); a tensile stress on the M O M bonds is accommodated by the formation of hexagonal polytypes [4].

Product Details

ISBN-13:	9783540675228
Publisher:	Springer Berlin Heidelberg
Publication date:	03/26/2001
Series:	Structure and Bonding , #98
Edition description:	2001
Pages:	239
Product dimensions:	6.14(w) x 9.21(h) x 0.03(d)

Table of Contents

General Considerations.- Transport Properties.- Local Atomic Structure of CMR Manganites and Related Oxides.- Optical Spectroscopic Studies of Metal-Insulator Transitions in Perovskite-Related Oxides.