Effect of Chemical Pressure on High Temperature Ferrimagnetic Double Perovskites Sr2CrOsO6 and Ca2CrOsO6

TL;DR

This study investigates how chemical pressure affects the structure and magnetic properties of double perovskites Sr2CrOsO6 and Ca2CrOsO6, revealing their ferrimagnetic insulating nature and magnetic ordering temperatures.

Contribution

It provides detailed structural and magnetic characterization of Sr2CrOsO6 and Ca2CrOsO6, including synthesis, neutron diffraction, and magnetization data, and explores the effects of chemical pressure on their properties.

Findings

Sr2CrOsO6 orders at 660 K with non-monotonic magnetization behavior.

Ca2CrOsO6 orders at 490 K without non-monotonic behavior.

No evidence found for the predicted canted magnetic structure in Sr2CrOsO6.

Abstract

The ordered double perovskites Sr2CrOsO6 and Ca2CrOsO6 have been synthesized and characterized with neutron powder diffraction, electrical transport measurements, and high field magnetization experiments. Sr2CrOsO6 and Ca2CrOsO6 crystallize with R-3 and P21/n space group symmetry, respectively. Both materials are found to be ferrimagnetic insulators with saturation magnetizations near 0.2 {\mu}B. Sr2CrOsO6 orders at 660 K, showing non-monotonic magnetization temperature dependence, while Ca2CrOsO6 orders at 490 K and does not show non-monotonic behavior. Evidence for a theoretically predicted canted magnetic structure in Sr2CrOsO6 is sought and not found.