Structure, magnetic properties, and magnetostriction of (Tb1-xNdx)(Fe0.4Co0.6)(1.9)

Citation
Zj. Guo et al., Structure, magnetic properties, and magnetostriction of (Tb1-xNdx)(Fe0.4Co0.6)(1.9), J APPL PHYS, 86(11), 1999, pp. 6310-6314
Citations number
14
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF APPLIED PHYSICS
ISSN journal
00218979 → ACNP
Volume
86
Issue
11
Year of publication
1999
Pages
6310 - 6314
Database
ISI
SICI code
0021-8979(199912)86:11<6310:SMPAMO>2.0.ZU;2-U
Abstract
The structure and magnetostriction of (Tb1-xNdx)(Fe0.4Co0.6)(1.9) (0 < x < 1) alloys have been investigated at room temperature and the magnetic prope rties determined over the temperature range 1.5-300 K. It was found that th e matrix of (Tb1-xNdx)(Fe0.4Co0.6)(1.9) is essentially that of a (Tb,Nd) (F e,Co)(2) phase with a MgCu2-type cubic Laves structure for all values of x. The lattice parameter of the Laves phase increases from 0.7297 to 0.7363 n m as x increases from 0 to 1 and obeys Vegard's law. We have measured the C urie temperature to decrease with increasing x from 667 K for Tb(Fe0.4Co0.6 )Fe-1.9 to 454 K for Nd(Fe0.4Co0.6)Fe-1.9. The resultant macroscopic magnet ization becomes zero when x = 0.45 at a temperature of 1.5 K. At 300 K, a s lightly smaller value of x is found to produce no resultant magnetization, and the spontaneous magnetostriction constant lambda(111) decreases slowly with increasing Nd content and vanishes abruptly from a value of 1630 x 10( -6) when x > 0.65. The polycrystalline isofield magnetostriction curves exh ibit a minimum at x = 0.45 and a peak at x = 0.65. The observed behavior ca n be explained on the basis of opposing rare-earth Tb and Nd moments and an anisotropy minimum close to x = 0.65. As the temperature is reduced below 300 K, the spin reorientation occurs at greater Nd concentrations. (C) 1999 American Institute of Physics. [S0021-8979(99)05423-7].