Magnetization, coercivity, and remanence in amorphous terbium{endash}iron metalloid alloys
- Department of Applied Physics, University of Hull, Hull, HU6 7RX (United Kingdom)
- Physikalisch Technische Bundesanstalt, 38116 Braunschweig (Germany)
Crystalline terbium{endash}iron compounds generate large magnetostrictive strains but for practical application require relatively large fields to overcome magnetocrystalline anisotropy. Their amorphous counterparts are magnetically softer and yet potentially useful magnetostrictive strains are still exhibited due to the presence of the Tb ions. As part of our investigation into the origins and magnitudes of the magnetostriction in amorphous rare earth{endash}iron alloys, their magnetic properties have been subjected to close examination. Melt-spun ribbons of TbFe{sub 2} containing between 3 and 14 at.{percent} boron were prepared and shown to be amorphous ({gt}6 at.{percent} B). The field and temperature dependences of magnetization have been measured in the region 4.5 K{lt}T{lt}300 K with fields up to 5 T using a superconducting quantum interference device magnetometer. The temperature dependences of coercivity and remanence have been determined. Zero field and field cooled magnetization curves indicate a spin freezing temperature {approximately}240 K. Analyzing the demagnetization curves in terms of the random anisotropy model proposed by Harris, Plischke, and Zuckermann (HPZ) [R. Harris, M. Plischke, and M. J. Zuckermann, Phys. Rev. Lett. {bold 31}, 160 (1974)] shows that the anisotropy and exchange energy in (TbFe{sub 2}){sub 1{minus}x}B{sub x} are of comparable magnitudes. Coupled with the sharp decrease of the anisotropy with increasing temperature this leads to an interesting thermal behavior of the remanence with a local minimum at {approximately}140 K. Different concentrations of boron seem to have no significant effect on the magnetic properties. Boron acts purely as a {open_quotes}glass former{close_quotes} necessary for producing amorphous TbFe{sub 2} by rapid cooling. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 496637
- Report Number(s):
- CONF-961141-; ISSN 0021-8979; TRN: 97:016320
- Journal Information:
- Journal of Applied Physics, Vol. 81, Issue 8; Conference: 41. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 12-15 Nov 1996; Other Information: PBD: Apr 1997
- Country of Publication:
- United States
- Language:
- English
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