Multiple spin reorientation transitions in Ga3+ substituted DyCrO3

Abstract

Single phase DyCr1-xGaxO3 (0≤x≤0.5) samples were synthesized successfully by sol-gel method. Magnetic measurements results indicate the Ga3+ substituted samples exhibit multiple spin reorientation transitions Γ2→Γ4→Γ2→Γ1 though the pure DyCrO3 sample does not exhibit spin reorientation transition. This is first time to observe three types of spin reorientation transitions simultaneously in a rare earth orthochromite sample. The stability of the spin reorientation transitions upon cooling field were also studied. Additionally, the temperature dependent inverse susceptibility exhibits an downward derivation from Curie-Weiss behavior above Néel temperature, indicating the presence of Griffiths phase in the Ga3+ substituted samples. The occurrence of such rich magnetic structures can be attributed to the fact that Ga3+ substitution weakens the exchange interaction between Cr3+ ions as well as between rare earth ion (R3+) and Cr3+ ions more effectively in DyCrO3, as Dy3+ has the highest effective magnetic moment among all rare earth ions. The multiple spin reorientation transitions make DyCr1-xGaxO3 as promising candidate materials for magnetic switching devices.