Microstructure, Magnetism and Magnetic Field Induced-Strain in Er-Doped Co-Ni-Al Polycrystalline AlloyMicrostructure, Magnetism and Magnetic Field Induced-Strain in Er-Doped Co-Ni-Al Polycrystalline Alloy

Access Restriction
Subscribed

 Author Ju, Jia ♦ Lou, Shuting ♦ Yan, Chen ♦ Yang, Liu ♦ Li, Tao ♦ Hao, Shuai ♦ Wang, Xingyi ♦ Liu, Huan Source SpringerLink Content type Text Publisher Springer US File Format PDF Copyright Year ©2017 Language English
 Subject Keyword Martensite ♦ intermetallics ♦ magnetic properties ♦ shape memory effect ♦ magnetic field-induced strain ♦ Optical and Electronic Materials ♦ Characterization and Evaluation of Materials ♦ Electronics and Microelectronics, Instrumentation ♦ Solid State Physics Abstract A large magnetic field-induced strain (MFIS) was discovered in single-crystal alloys, whereas it is proven difficult for such apparent strain values to be obtained in polycrystalline alloys. In order for an apparent strain discovery to occur, the polycrystalline Co-Ni-Al system was doped by 0–1 at.% of Er and the effects of doping on microstructure, magnetism and MFIS were studied via scanning electron microscopy, x-ray diffraction, transmission electron microscopy and vibrating sample magnetometer in the present work. The microstructure of the alloy was a dual-phase microstructure, including the matrix and the γ phase. Following the Er doping, the γ phase was continuously coarsened, forming a network of precipitates surrounding the grains. Also, a Co-Er-rich intermetallic compound was formed in the Co-rich γ phase when the Er content exceeded 0.1 at.%. The martensitic transformation temperature has a decreasing tendency during the Er being doped from 0 at.% to 1 at.% and the martensitic structure of the sample is of the L1$_{0}$ type, forming twin grains in the (111) twinning plane. On the contrary, the magnetic properties were improved by Er doping, especially saturation magnetization and magneto-crystalline anisotropy constantly increased to 60.45 emu/g and 3.13 × 10$^{6}$ erg/cm$^{3}$ when the Er content reached 1 at.%, respectively. Also, the strain recovery ratio (R $_{s}$) of Co-Ni-Al-Er alloys can be enhanced by thermo-mechanical cycles and Er doping. At 5% of the total strain, the R $_{s}$ value exceeded 83% following thermo-mechanical cycles when the Er doping was 1 at.%. The strain in the applied magnetic field was increased by Er doping and an excess of 140 ppm of MFIS was obtained in the polycrystalline Co-Ni-Al-Er alloys. ISSN 03615235 Age Range 18 to 22 years ♦ above 22 year Educational Use Research Education Level UG and PG Learning Resource Type Article Publisher Date 2017-02-10 Publisher Place New York e-ISSN 1543186X Journal Journal of Electronic Materials Volume Number 46 Issue Number 4 Page Count 8 Starting Page 2540 Ending Page 2547