TY - JOUR
T1 - Microstructures and magnetic properties of rapidly solidified Ni54 Fe27-2x Ga19+2x ferromagnetic Heusler alloys
AU - Aich, S.
AU - Das, S.
AU - Al-Omari, I. A.
AU - Alagarsamy, P.
AU - Chowdhury, S. G.
AU - Chakraborty, M.
AU - Shield, J. E.
AU - Sellmyer, D. J.
N1 - Funding Information:
This work was supported by the Indian Institute of Technology (IIT)-Kharagpur, India, and the National Metallurgical Laboratory (NML) Jamshedpur, India. I.A.A.-O. and D.J.S. would also like to thank the Sultan Qaboos University and the U.S. DOE, respectively, for the support under Grant Nos. IG-SCI-PHYS-07-05 and DE-F602-04ER46152, respectively.
PY - 2009
Y1 - 2009
N2 - Rapidly solidified Ni54 Fe27-2x Ga19+2x (x=0, 1, 2, 3, and 4) ferromagnetic shape memory alloys were made by melt-spinning with variation of Fe and Ga contents to report on the martensitic phase transformation, microstructures, and magnetic properties. Rapid solidification produced pure L 21 phase by preventing the formation of γ -phase. To study the effect of heat treatment on the phase transitions, microstructures, and the magnetic properties, the melt-spun ribbons were partly heat treated at different temperatures of 800, 900, 1000, 1100, and 1200 K with holding times of 5, 10, and 15 min followed by either water quenching or air cooling. The microstructures of the as-spun ribbons as revealed by electron microscopy studies exhibited a gradual transition from cellular to dendritic structure with increasing Ga concentration and with the presence of some internal martensitic twin bands at higher Ga content. The ribbons exhibited very low coercivity with high saturation magnetization, as high as ∼87 emu/g (decreasing with Ga concentration). The above-ambient Curie temperature (TC) and the subambient martensitic transition temperature (Tm) were observed to be ∼320 and ∼195 K, respectively. At higher heat treatment temperatures formation of ductile γ phases was observed.
AB - Rapidly solidified Ni54 Fe27-2x Ga19+2x (x=0, 1, 2, 3, and 4) ferromagnetic shape memory alloys were made by melt-spinning with variation of Fe and Ga contents to report on the martensitic phase transformation, microstructures, and magnetic properties. Rapid solidification produced pure L 21 phase by preventing the formation of γ -phase. To study the effect of heat treatment on the phase transitions, microstructures, and the magnetic properties, the melt-spun ribbons were partly heat treated at different temperatures of 800, 900, 1000, 1100, and 1200 K with holding times of 5, 10, and 15 min followed by either water quenching or air cooling. The microstructures of the as-spun ribbons as revealed by electron microscopy studies exhibited a gradual transition from cellular to dendritic structure with increasing Ga concentration and with the presence of some internal martensitic twin bands at higher Ga content. The ribbons exhibited very low coercivity with high saturation magnetization, as high as ∼87 emu/g (decreasing with Ga concentration). The above-ambient Curie temperature (TC) and the subambient martensitic transition temperature (Tm) were observed to be ∼320 and ∼195 K, respectively. At higher heat treatment temperatures formation of ductile γ phases was observed.
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U2 - 10.1063/1.3073839
DO - 10.1063/1.3073839
M3 - Article
AN - SCOPUS:65249151251
SN - 0021-8979
VL - 105
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 7
M1 - 07A943
ER -