Large variations in the magnetic ordering behavior of EuCu2As2 with the application of external pressure and magnetic field

Abstract

The influence of external pressure on the electrical transport and magnetic properties of EuCu2As2, crystallizing in a ThCr2Si2-type structure, is reported. The system is known to be an antiferromagnet below TN ≈ 15 K in the absence of external magnetic fields. We find that there is a gradual reduction of TN with the application of a magnetic field with an extrapolated value of the critical field of around 18 kOe which can drive TN to zero. Electrical resistivity under pressure (<11 GPa) reveals that the magnetic ordering temperature is pushed up dramatically to higher temperatures which is quite interesting if compared with the behavior in isostructural FeAs-based systems containing Eu. Above 7 GPa, the pressure-induced state appears to be ferromagnetic. The results thus reveal interesting changes in the magnetic ordering behavior of this compound with increasing pressure and magnetic fields.