Strong magnetic anisotropy in PrRu₂Ga₈ and PrCo₂Al₈ single crystals

Abstract

Single crystals of LnRu2Ga8 and LnCo2Al8 (Ln = La and Pr) were grown using a Ga/Al self-flux method. An orthorhombic CaCo2Al8-type structure with space group Pbam (No.55) of them was identified by XRD. LaRu2Ga8 and LaCo2Al8 are Pauli paramagnetic down to 2 K, while PrRu2Ga8 and PrCo2Al8 show antiferromagnetic order at 2.5 and 5 K, respectively. Strong magnetic anisotropy in PrRu<sub>2</sub>Ga<sub>8</sub> and PrCo<sub>2</sub>Al<sub>8</sub> single crystals was found by an anisotropic magnetic measurement. The field-induced ferromagnetic state was observed in both PrRu2Ga8 and PrCo2Al8 for H||c. However, in the case of H⊥c, the antiferromagnetic state is robust. The strong magnetic anisotropy in PrRu2Ga8 and PrCo2Al8 is due to their anisotropic magnetic interactions that ferromagnetic interactions are dominant in the case of H||c while antiferromagnetic interactions for H⊥c.