ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The ε-MnZn alloy (disordered hcp structure) containing 15 at. % Mn seems to be ferromagnetic below about 200 K; the magnetization σ in a field H of 9.5 kOe amounts to 26 emu/g at a temperature T of 4.2 K. The σ vs T curve in lower H, however, shows a maximum, suggesting mictomagnetism. This is verified by the existence of a hump on the ac susceptibility χac vs T curve. The σ versus concentration curve shows a maximum at 15 at. % Mn. The χac vs T curves for the 12 at. % Mn alloy show a cusp at 45 K in addition to the hump between 80 and 180 K, suggesting a spin glass state. Both the cusp and the hump are suppressed by a dc magnetic field applied parallel to the ac field. The micromagnetic behavior becomes more pronounced for the Mn richer alloys which show only the hump in the χac vs T curve. The σ vs T curves exhibit a magnetic field cooling effect below a freezing temperature Tf. The values of Tf for the alloys containing 20, 30, and 45 at. % Mn are 38, 50, and 75 K, respectively. Although the antiferromagnetic interaction predominates in the Mn rich alloys, a long-range antiferromagnetic order may not be expected because of the random distribution of Mn moments. The 25 at. % Mn alloy shows strong ferromagnetism, if the atomic ordering in the hcp lattice is realized. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.361907
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