Study of the martensitic transition in Ni-Mn-Sn-Ti ferromagnetic shape memory alloys

Federico Guillermo Bonifacich,Vicente Sánchez-Alarcos,Damián Gargicevich,Ricardo Raúl Mocellini,Aldo Marenzana,Osvaldo Agustín Lambri,Vicente Recarte,José Ignacio Pérez-Landazábal,Griselda Irene Zelada,Fernando Plazaola

doi:10.1590/s1517-707620180002.0379

Abstract

ABSTRACT In the present work, mechanical spectroscopy measurements as a function of temperature and strain have been performed in (at.%) Ni50Mn37Sn13-xTix (x=0, 0.5 and 2) ferromagnetic shape memory alloys in order both to study martensitic transition phenomenon and also to determine its temperature of appearance. For mechanical spectroscopy measurements, a five elements piezoelectric device recently developed has been used. In addition, other characterization techniques as, differential thermal analysis and superconducting quantum interference magnetic spectroscopy, were also used. Besides, relaxation processes near the martensitic transition temperature have been also observed.

Highlights

Ni–Mn–X (X = Ga, In, Sn, Sb) alloys are currently attracting considerable attention due to the peculiar multifunctional properties that show as a result of coupling between structure and magnetism [1,2,3]
Differential Thermal Analysis (DTA) and SQUID measurements were performed in order to determine the martensitic transformation (MT) temperature for three different compositions
In Ti2 sample (see Figure 3(c)), it can be detected another process just below the MT temperature; which can be inferred by the appearance of both the peak in the SQUID spectrum and the hump in the low temperature tail in the DTA reaction peak

Summary

Introduction

Ni–Mn–X (X = Ga, In, Sn, Sb) alloys are currently attracting considerable attention due to the peculiar multifunctional properties that show as a result of coupling between structure and magnetism (namely giant magnetoresistance, magnetic shape memory effect or large magnetocaloric effect) [1,2,3]. In Ni–Mn–Z alloys (Z = In, Sn, Sb) the ferromagnetism of the austenite vanishes at the MT, concurrently with the appearance of antiferromagnetic correlations, resulting in a martensitic phase with lower magnetic moment [5,6,7] In this latter case, the metamagnetic character of the MT gives rise to new interesting phenomena, such as: the magnetic-field induction of the MT, the kinetic arrest of the martensite, the exchange bias or the observation of a peculiar isothermal character in the MT. These phenomena have been widely studied in recent years [8,9,10,11]

Methods

Results

Conclusion