Introduction

In recent years, the magnetocaloric effect (MCE) in various magnetic materials has been extensively studied experimentally and theoretically, not only because of their great potential for magnetic refrigeration applications but also for further understanding the fundamental physical properties of the materials. [1-13] The MCE manifests as an isothermal magnetic entropy change ( SM) or an adiabatic temperature change ( Tad) when the magnetic material is exposed to a varying magnetic field. Magnetic refrigeration based on the MCE is advantageous being an environment friendly and energy efficient refrigeration mechanism, which is expected to be an important future cooling technology. [1-3] A large value of MCE is considered to be the most important requirement of the application, and therefore it is desirable to find new materials with large MCE especially at low magnetic fields and with a wide temperature range. Recently, some rare-earth based compounds with an antiferromagnetic (AFM) or a ferromagnetic (FM) have been found to possess not only large magnetic entropy change but also a small hysteresis loss. [9-15]

The intermetallic compounds of the EuT2X2 (T = Fe, Co, Cu etc.; X = Si, P, B etc.) with the ThCr2Si2-type crystal structure have been extensively studied due to their interesting physical properties. Depending on the constituent element or composition, various properties like superconductivity, magnetic ordering, Kondo effect, heavy-fermion properties, valence fluctuation and large MCE, etc. are observed. [16-23] EuFe2As2 are attracting much attention due to the discovery of Fe-based superconductivity. [19, 20] EuFe2P2 is a rare Eu-containing dense Kondo lattice compound.

[21] Recently, a ferromagnetic transition around 51 K for EuCu1.75P2 was confirmed by examining the temperature dependence of magnetization and electrical resistivity. [22]