Surface modifications and tailoring magnetism in Ni48·4Mn28.8Ga22.8 films by 120 keV proton irradiation

Autor: Zhai-Ping Yang, Zhiyong Gao, Wei Cai, Bin Sun
Rok vydání: 2018
Předmět:
Zdroj: Intermetallics. 98:106-114
ISSN: 0966-9795
DOI: 10.1016/j.intermet.2018.04.015
Popis: Proton irradiation was performed to investigate the surface modifications and tailoring magnetism of ferromagnetic austenitic Ni48·4Mn28.8Ga22.8 films under different proton fluences. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) results show that seven-layered modulated (7M) martensite can be produced on the surface of austenitic Ni48·4Mn28.8Ga22.8 films at the proton fluence values of 1.0 × 1016 and 2.0 × 1016 p/cm2. The phase transformation temperatures and magnetic properties of the irradiated Ni48·4Mn28.8Ga22.8 films also depend on the proton fluence. Particularly, the magnetism of Ni48·4Mn28.8Ga22.8 films can be tailored by applying proton irradiation under different fluences. When the proton fluence is small as 1.0 × 1015 p/cm2, the saturation magnetization (MS) and the magnetic anisotropy constant (K1) of the irradiated Ni48·4Mn28.8Ga22.8 films can be improved. However, proton irradiation at a fluence as high as 2.0 × 1016 p/cm2 will deteriorate the magnetic performance of the Ni48·4Mn28.8Ga22.8 films. These experimental results are extremely meaningful to improve the magnetic-field-induced strain of Ni-Mn-Ga alloys via irradiation-induced modification or understand the damaged microstructure and magnetic properties of Ni-Mn-Ga alloys under extreme environment.
Databáze: OpenAIRE
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