1. A low temperature anomaly observed in off-stoichiometric Ni–Mn–Ga system studied by higher harmonic ac-susceptibility measurements
- Author
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Pawel Kamasa, Ratnamala Chatterjee, Vladimir Khovaylo, Vijay K. Srivastava, Saurabh Kumar Srivastava, Anupam Joshi, and Lajos K. Varga
- Subjects
Tetragonal crystal system ,Materials science ,Differential scanning calorimetry ,Physics and Astronomy (miscellaneous) ,Metastability ,X-ray crystallography ,Analytical chemistry ,Crystal structure ,Anomaly (physics) ,Single crystal ,Magnetic susceptibility - Abstract
Results of fundamental and third order ac susceptibility measurements in a Ni49Mn29Ga22 single crystal demonstrate that higher harmonics of ac-susceptibility measurement is an excellent tool to identify transitions/anomalies originating from different magnetic substructures that remain undetected by usual dc susceptibility measurements. Anomaly observed at low temperature (∼150 K) has also been explored by differential scanning calorimetry, temperature dependent x-ray diffraction, and transmission electron microscopy measurements. The results demonstrate that the magnetic subsystem in Ni–Mn–Ga is unstable at low temperatures not only for metastable modulated crystal structure but also for very stable nonmodulated tetragonal structure.
- Published
- 2010