Thermo-magnetic characterization of phase transitions in a Ni-Mn-In metamagnetic shape memory alloy
|Author/s||Romero Landa, Francisco Javier
Martín Olalla, José María
Blázquez Gámez, Javier Sebastián
Gallardo Cruz, María del Carmen
|Department||Universidad de Sevilla. Departamento de Física de la Materia Condensada|
|Abstract||The partially overlapped ferroelastic/martensitic and para-ferromagnetic phase transitions of a Ni50.53Mn33.65In15.82 metamagnetic shape memory alloy have been studied from calorimetric, magnetic and acoustic emission ...
The partially overlapped ferroelastic/martensitic and para-ferromagnetic phase transitions of a Ni50.53Mn33.65In15.82 metamagnetic shape memory alloy have been studied from calorimetric, magnetic and acoustic emission measurement. We have taken advantage of the existence of thermal hysteresis of the first order ferroelastic/martensitic phase transition (~2.5 K) to discriminate the latent heat contribution Delta=H 7.21(15)kJ/kg and the specific heat contribution Delta H_c =216(1)J/kg to the total excess enthalpy of the phase transition. The specific heat was found to follow a step-like behavior at this phase transition. The intermittent dynamics of the ferroelastic/martensitic transition has been characterized as a series of avalanches detected both from acoustic emission and calorimetric measurements. The energy distribution of these avalanche events was found to follow a power law with a characteristic energy exponent 2 which is in agreement with the expected value for a system undergoing a symmetry change from cubic to monoclinic. Finally, the critical behavior of the para-ferromagnetic austenite phase transition that takes place at ~311 K has been studied from the behavior of the specific heat. A critical exponent 0.09 has been obtained, which has been shown to be in agreement with previous values reported for Ni-Mn-Ga alloys but different from the critical divergence reported for pure Ni.
|Funding agencies||European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER)
Comisión Interministerial de Ciencia y Tecnología (CICYT). España
|Citation||Romero Landa, F.J., Martín Olalla, J.M., Blázquez Gámez, J.S., Gallardo Cruz, M.d.C., Soto-Parra, D., Vives, E. y Planes, A. (2021). Thermo-magnetic characterization of phase transitions in a Ni-Mn-In metamagnetic shape memory alloy. Journal of Alloys and Compounds, 887, 161395.|