Barocaloric and magnetocaloric effects in (MnNiSi)1-x(FeCoGe)x

Tapas Samanta, Louisiana State University
Pol Lloveras, Universitat Politècnica de Catalunya
Ahmad Us Saleheen, Louisiana State University
Daniel L. Lepkowski, Louisiana State University
Emily Kramer, Louisiana State University
Igor Dubenko, Southern Illinois University Carbondale
Philip W. Adams, Louisiana State University
David P. Young, Louisiana State University
Maria Barrio, Universitat Politècnica de Catalunya
Josep Ll Tamarit, Universitat Politècnica de Catalunya
Naushad Ali, Southern Illinois University Carbondale
Shane Stadler, Louisiana State University


(MnNiSi)1-x(FeCoGe)x undergoes a magnetostructural phase transition near room temperature that is acutely sensitive to applied hydrostatic pressure, which presents as a marked shift in the martensitic transition temperature (TM) by about -7.5 K/kbar. The magnetostructural transition can therefore be induced by applied hydrostatic pressure or by magnetic field. The barocaloric and magnetocaloric effects were measured across TM (for the sample with x = 0.38), and the corresponding entropy changes were +74 J/kg K (P = 2.7 kbar) and -58 J/kg K (μ0H = 5 T), respectively. It was observed that the transition entropy change increases with pressure, which results in an enhancement of the barocaloric effect. Our measurements show that the transformed phase fraction associated with magnetostructural transition does not depend on pressure and, therefore, this enhancement cannot be attributed to a pressure-assisted completion of the phase transformation.