Change from antiferromagnetic to ferromagnetic order in the pseudo-ternary series TbNi1-xCuxAl

G. Ehlers, D. Ahlert, W. Miekeley, H. Maletta

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

In TbNiAl, which adopts the hexagonal ZrNiAl-structure, the Tb-site forms a triangular lattice in the a-b plane. The coupling between nearest neighbours was shown to be antiferromagnetic, giving rise to the formation of frustrated moments of Tb. TbNiAl has two antiferromagnetic phases which differ in the ordering of the frustrated spins. On the other hand, TbCuAl is a ferromagnet. It is shown by means of neutron diffraction that the stoichiometric substitution of Ni by a few per cent of Cu leads to an instant suppression of antiferromagnetism. The ordering temperature increases from TN =47 K for TbNiAl to TC = 55 K for TbNi0.90Cu0.10Al since the number of frustrated bonds is strongly reduced. In the range 0.01 ≤ x ≤ 0.10, surprisingly, both ferro- and antiferromagnetic types of order coexist in different domains. The volume fraction with antiferromagnetic order decreases with both increasing x in different samples and with increasing temperature below TC in one sample. Compounds in the range 0.1 <x ≤1.0 are ferromagnets but at intermediate concentrations 0.60 ≤x ≤0.80, a dominant short-range magnetic order is observed. The results are discussed with a local magnetic exchange coupling between Tb spins.

Original languageEnglish
Pages (from-to)670-672
Number of pages3
JournalPhysica B: Physics of Condensed Matter
Volume234-236
DOIs
StatePublished - Jun 2 1997
Externally publishedYes

Keywords

  • Magnetic order
  • Powder diffraction
  • RKKY interaction

Fingerprint

Dive into the research topics of 'Change from antiferromagnetic to ferromagnetic order in the pseudo-ternary series TbNi1-xCuxAl'. Together they form a unique fingerprint.

Cite this