Magnetization study of the kinetic arrest of martensitic transformation in as-quenched Ni 52.2 Mn 34.3 In 13.5 melt spun
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Magnetization study of the kinetic arrest of martensitic transformation in as-quenched Ni52.2Mn34.3In13.5 melt spun ribbons F.M. Lino-Zapata1, J.L. Sánchez Llamazares1, D. Ríos-Jara1, A.G. Lara-Rodríguez2, and T. García-Fernández3 1 Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José 2055 Col. Lomas 4ª, San Luis Potosí, S.L.P. 78216, México. 2 Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n, Ciudad Universitaria, México D.F. 04510, México. 3 Universidad Autónoma de la Ciudad de México, Prolongación San Isidro 151,Col. San Lorenzo Tezonco, México DF, C.P. 09790, México
ABSTRACT The kinetic arrest of martensitic transformation (MT) has been observed in as-solidified Ni52.2Mn34.3In13.5 melt spun ribbons. The main characteristics of this unusual field-induced magneto-structural phenomenon have been determined through a dc magnetization study. The sample studied was fabricated by rapid solidification using the melt spinning technique at a high quenching rate of 48 ms-1. At room temperature, it is a single phase austenite (AST) with the bcc B2-type crystal structure and Curie temperature of TCA=285 K. With decreasing temperature, the austenite phase transforms into the martensite phase (MST) with TCM185 K at a starting martensitic transition temperature of MS=275 K. A moderate but progressive kinetic arrest of the AST to MST transformation has been observed for magnetic field values above H=10 kOe and was studied up to Hmax= 90 kOe. The metastable character of the non-equilibrium field-cooled state is revealed by the decreasing behavior of the saturation magnetization under a large magnetic field of 50 kOe after temperature cycling from 10 K to 150 K. The total magnetization difference between the zero field-cooling and field-cooling pathways of the temperature dependence of magnetization shows irreversible and reversible components and the former decreases with decreasing temperature. INTRODUCTION In the last few years, considerable attention has been paid to the investigation of the physical phenomena related to the first-order structural martensitic transition in ferromagnetic shape memory alloys of the ternary alloy systems Ni-Mn-X (X= Sn, In, Sb). The most important of these are magnetic superelasticity [1], the giant inverse magnetocaloric effect [1-4], and large magneto-resistance [5-7]. In connection with the structural transition, the most important phenomenon induced by the magnetic field in these materials is the field-induced reverse martensitic transformation [8, 9]. However, in some bulk Ni-Mn-In based alloys [10-13] and melt spun Mn-Ni-In alloy ribbons [14] the kinetic arrest of the martensitic transformation has been reported (i.e., a volume fraction of austenite remains frozen into an equilibrium martensitic matrix when the material is cooled below the martensitic final structural transition temperature M under the application of a static f
magnetic field beyond a certain critical value). In this paper, we report the occurrence of this
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