Structural and cryogenic magnetic properties of RENiIn (RE = Pr, Nd, Dy and Ho) compounds.

The crystal structures, magnetic properties and magneto-caloric effects (MCEs) of RENiIn (RE = Pr, Nd, Dy and Ho) compounds were investigated. The results indicate that PrNiIn and NdNiIn compounds have a tetragonal MoFeB-type structure belonging to the P4/mbm space group and undergo a second-order paramagnetic to ferromagnetic (PM to FM) transition at a Curie temperature (T) of 7.5 and 10.5 K, respectively, whereas DyNiIn and HoNiIn compounds have an orthorhombic MnAlB-type structure belonging to the space group Cmmm and possess a magnetic transition from PM to antiferromagnetic (AFM) at a Néel temperature T of 19 and 10.5 K together with a first-order field induced metamagnetic transition, respectively. Moreover, an additional magnetic transition at a lower temperature of around 5.5 K is detected for the HoNiIn compound. A considerable reversible magneto-caloric effect is observed accompanying the magnetic phase transition, and the maximum values of the magnetic entropy change (-ΔS) of the present RENiIn series compounds are determined to be 9.3, 11.5, 6.4 and 11.5 J kg K with a magnetic field change (ΔH) of up to 0-5 T for RE = Pr, Nd, Dy and Ho, respectively.