Magnetic and transport properties of SrFeOx

被引：29

作者：

Williams, G. V. M. ^{[1
]}

Hemery, E. K. ^{[1
,2
]}

McCann, D. ^{[1
]}

机构：

[1] MacDiarmid Inst Adv Mat & Nanotechnol, Lower Hutt 5040, New Zealand

[2] Victoria Univ, MacDiarmid Inst Adv Mat & Nanotechnol, Wellington 6140, New Zealand

来源：

PHYSICAL REVIEW B | 2009年 / 79卷 / 02期

关键词：

antiferromagnetic materials; exchange interactions (electron); Fermi level; frustration; magnetic moments; magnetoresistance; Neel temperature; spin glasses; strontium compounds; thermoelectric power; SPIN-GLASSES; THERMOELECTRIC-POWER; NI-MN; THERMOPOWER; OXIDES; MODEL;

D O I：

10.1103/PhysRevB.79.024412

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We report the results from magnetic and transport measurements on SrFeOx where we focus on oxygen contents about the Sr4Fe4O11 phase (x=2.75) that antiferromagnetically orders at similar to 230 K. We find an exchange-bias-like effect in Sr4Fe4O11 that commences near the Fe(2) moment Neel temperature (similar to 230 K). While there is a weak spin-glass component, possibly arising from spin-frustrated moments on the Fe(1) sites, the spin-glass temperature is significantly less than 230 K, and hence the exchange-bias-like effect is unlikely to be due to a spin glass. The exchange-bias-like effect clearly arises from an exchange interaction term that includes the Fe(2) spins but its exact nature is not clear and awaits a detailed theoretical study. Room-temperature thermopower measurements show a large change in sign for oxygen contents on either side of the Sr4Fe4O11 phase, which we show can be qualitatively interpreted by assuming that the Fermi level is within a narrow band. High-field resistivity measurements show a large magnetoresistance that commences near the Sr4Fe4O11 Neel temperature.

引用

页数：7