Coupled magnetostructural transformations in melt-spun Ni55Mn19.6Ga25.4 ribbon: An electron spin resonance study

Abstract

Electron spin resonance study has been carried out on melt-spun ribbon of Ni 55 Mn 19.6 Ga 25.4 exhibiting coupled magnetostructural transition. The correlation of electron spin resonance, thermal and magnetic results permitted a clear distinction of various phases and their transformations. Both structural and magnetic transitions coexist in the temperature range 300Յ T Յ 310 leading to four different magnetic phases namely paramagnetic austenite, ferromagnetic austenite, paramagnetic martensite, and ferromagnetic martensite. The sample exhibits a single paramagnetic austenite phase above 310 K while it shows a ferromagnetic martensite phase below 260 K.