Mössbauer Studies for Exploring CMR and TMR Perovskites

Abstract

In the present review we show a series of recent studies with the aim of exploring the electronic and magnetic structure of materials with perovskite structure and strong magnetoresistance effect. The examined samples include Sr_2-xA_xFeMO₆ (A = Ca, Ba and M = Mo, Re, Ru) double perovskites with x = 0 and 0.1 and iron doped La_0.8Sr_0.2Fe_yCo_1-yO_3-δ cobaltate perovskites with 0 ≤ y ≤ 0.3. Besides understanding the basic electronic and magnetic interactions presented by these compounds, we have tried to trace nanoscale phase separation, which has been introduced as a key feature for both colossal and intrinsic tunneling magnetoresistance recently.