Ni–Mn–Ga thin films produced by pulsed laser deposition

P. G. Tello, F. J. Castaño, R. C. O'Handley, S. M. Allen, M. Esteve, F. Castaño, A. Labarta, X. Batlle
2002 Journal of Applied Physics  
Polycrystalline Ni-Mn-Ga thin films have been deposited by the pulsed laser deposition ͑PLD͒ technique, using slices of a Ni-Mn-Ga single crystal as targets and onto Si ͑100͒ substrates at temperatures ranging from 673 K up to 973 K. Off-stoichiometry thin films were deposited at a base pressure of 1ϫ10 Ϫ6 Torr or in a 5 mTorr Ar atmosphere. Samples deposited in vacuum and temperatures above 823 K are magnetic at room temperature and show the austenitic ͕220͖ reflection in their x-ray
more » ... eir x-ray diffraction patterns. The temperature dependences of both electrical resistance and magnetic susceptibility suggest that these samples exhibit a structural martensitic transition at around 260 K. The magnetoresistance ratio at low temperature can be as high as 1.3%, suggesting the existence of a granular structure in the films.
doi:10.1063/1.1452222 fatcat:oedblvi6tbe2bi2t47c64ustdy