Magnetic studies of Ca1-xMxRuO3 (M=La and Sr)

TL;DR

This study investigates the magnetic properties of Ca1-xMxRuO3 (M=La, Sr) compounds, revealing how substitution affects magnetic ordering, hysteresis, and coercivity across different compositions and temperatures.

Contribution

It provides detailed magnetic characterization of Ca1-xMxRuO3 with La and Sr substitutions, highlighting the evolution of magnetic phases and hysteresis behavior.

Findings

La substitution induces antiferromagnetic order at low temperatures.

Sr substitution leads to ferromagnetic behavior with large hysteresis.

Coercive fields vary significantly with composition and temperature.

Abstract

CaRuO3 is a perovskite with an orthorhombic distortion and shows the characteristics of spin-glass behavior below TC=87 K. The La3+ substitution for Ca2+ in Ca1-xLaxRuO3 samples, induces a disorder in the Ca site (the A site) and the system becomes antiferromagnetically (AFM) ordered with TN = 58 and 19 K for x=0.1 x=0.5 respectively. In the Ca1-xSrxRuO3 system, the Ca0.8Sr0.2RuO3 sample is canted-AFM ordered at 107 K. The compounds with higher Sr concentration display ferromagnetic behavior and the saturation moment increases with Sr. Huge magnetic hysteresis loops are obtained at low temperatures. The coercive field (HC) decreases with Sr. For x=0.4 HC =9.5 kOe (at 5 K) whereas for SrRuO3 HC =2.4 kOe. For x=0.4 and 0.6, HC decreases sharply with temperature and than increases again with a peak at 95 and 115 K, respectively. On the other hand, for SrRuO3, HC remains practically unchanged up to 50 K and shows a peak at 90 K and than decrease sharply up to TC =165 K.