Stress-induced large Curie temperature enhancement in Fe64Ni36 Invar alloy

Pedro Gorria (1) , David Martínez-Blanco (1) , Maria J. Perez (1) , Jesús A. Blanco (1) , Antonio Hernando (2) , María A. Laguna-Marco (3) , Daniel Haskel (3) , Narcizo M. Souza-Neto (3) , Ronald I. Smith (4) , W.G. Marshall (4) , Gaston Garbarino (5) , Mohamed Mezouar (5) , Alejandro Fernandez-Martinez (6, 7) , Jesús Chaboy (8) , L. Fernandez Barquín (9) , J. A. Rodriguez Castrillón (10) , M. Moldovan (10) , J. I. Garcia Alonso (10) , Jianzhong Zhang (11) , Anna Llobet (11) , J. S. Jiang (12)

1 Departamento de Física
2 Instituto de Magnetismo Aplicado
3 APS - Advanced Photon Source [ANL]
4 ISIS Facility
5 ESRF - European Synchrotron Radiation Facility
6 ILL - Institut Laue-Langevin
7 LGIT - Laboratoire de Géophysique Interne et Tectonophysique
8 CSIC - ICMA and Departamento de Física de la Materia Condensada
9 CITIMAC, Facultad de Ciencias
10 Department of Physical and Analytical Chemistry
11 Lujan Center for Neutron Scattering, LANL
12 MSD - Material Science Division [ANL]

We have succeeded in increasing up to 150 K the Curie temperature in the Fe64Ni36 invar alloy by means of a severe mechanical treatment followed by a heating up to 1073 K. The invar behavior is still present as revealed by the combination of magnetic measurements with neutron and x-ray techniques under extreme conditions, such as high temperature and high pressure. The proposed explanation is based in a selective induced microstrain around the Fe atoms, which causes a slight increase in the Fe-Fe interatomic distances, thus reinforcing ferromagnetic interactions due to the strong magnetoelastic coupling in these invar compounds.

Domaines: Planète et Univers [physics]

Pedro Gorria, David Martínez-Blanco, Maria J. Perez, Jesús A. Blanco, Antonio Hernando, et al.. Stress-induced large Curie temperature enhancement in Fe64Ni36 Invar alloy. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 80 (6), pp.064421. ⟨10.1103/PhysRevB.80.064421⟩. ⟨insu-00498748⟩