Phase diagram and transport properties of Y1-xNdxCo2 pseudo-binary alloys

A. T. Burkov, M. Takeda, A. Teruya, S. Watanabe, S. Hirakawa, Y. Hiranaka, A. Nakamura, M. Hedo, T. Nakama, K. Yagasaki, Y. Takaesu, K. Uchima, Y. Uwatoko

Research output: Contribution to journalArticlepeer-review

Abstract

The electrical resistivity ρ and the thermopower S of pseudo-binary Y1-xNdxCo2 alloys have been measured at temperatures from 2 to 300 K under pressures up to 3.5 GPa. NdCo2 is a ferromagnet with a Curie temperature T C of 98 K. In the ferromagnetic phase, it undergoes a 4f spin-reorientation transition at T R = 40 K. At this transition, the easy direction of 4f magnetization is changed from [100] at temperatures above T R to [110] below T R. The system phase diagram T C(x, P) and T R(x, P) is inferred from the temperature dependencies of the electrical resistivity and the thermopower. The Curie temperature of the alloys, TC decreases with decreasing Nd concentration x and vanishes around x c = 0.3. Above x c, the Curie temperature decreases with increasing pressure. The spinreorientation temperature weakly depends on the composition and on the pressure until it merges with T C. There is a large region of the phase diagram, partly overlapping with the ferromagnetic phase, where the cobalt 3d electron system is non-uniformly magnetized due to spatial fluctuations of the 4f-3d exchange field related to a random distribution of Nd 4f magnetic moments over the R sublattice. In this region, large static 3d magnetic fluctuations govern the electronic transport.

Original languageEnglish
Pages (from-to)2080-2083
Number of pages4
JournalJournal of the Korean Physical Society
Volume62
Issue number12
DOIs
Publication statusPublished - 2013 Jul
Externally publishedYes

Keywords

  • Electrical resistivity
  • Pressure effect
  • Thermopower

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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