Effect of Al substitution on magnetocaloric effect in La0.57Nd0.1Sr0.33Mn1−xAlxO3 (0.0 ≤ x ≤ 0.30) polycrystalline near room temperature

Abstract

We have investigated the effect of aluminum (Al) doping on the magnetic and magnetocaloric properties of La0.57Nd0.1Sr0.33Mn1−xAlxO3 (LNSMAO) (0.0≤x≤0.3). The Curie temperature TC of the prepared samples is found to be strongly dependent on the aluminum content and it spans between 238K and 342K. It has been analyzed by using two methods: a linear extrapolation of M (T) to zero magnetization and the thermodynamic model. With an increasing Al concentration, a systematic increase in the values of magnetic entropy is observed. The magnitude of the isothermal magnetic entropy (ΔSM) at the FM Curie temperature increases from 2.31J/kgK for x=0 to a maximum value of 3.58J/kgK for x=0.3 for a magnetic field change of 10kOe. Moreover, the relative cooling power (RCP) increases from 23J/kg to 68J/kg, respectively. Large magnetic entropy changes upon the application of a low magnetic field and a wide temperature range of TC suggest that these materials can be used as candidates for magnetic refrigerants.