Abstract. The magnetic properties and ⁵⁷Fe Mössbauer spectra of the compounds YFe₁₁TiH_x (x = 0, 1) were investigated. The magnetocrystalline anisotropy of YFe₁₁Ti and its hydride was studied by analysing the hard and easy magnetization curves of single crystal samples in the temperature range 4.2–300 K. The spontaneous magnetization was determined in wide temperature range 4.2–650 K. It is established that at T = 4.2 K magnetic anisotropy constants K₁ and K₂ for YFe₁₁TiH₁ single crystal reach values of 25.8 K f.u.⁻¹ and 0.24 K f.u.⁻¹, respectively. The Mössbauer effect spectra of YFe₁₁Ti and its hydride were analysed in terms of a model which takes into account the local environment of Fe atoms on three crystallographic sites (8f, 8j and 8i) and an influence of the random distribution of titanium on the 8i site. Upon hydrogenation both the hyperfine fields and the isomer shifts increase. These results are discussed in terms of the hydrogen-induced unit cell expansion and the electron charge transfer from the conduction band onto the H atoms.

A corrigendum for this article has been published in 2003 J. Phys.: Condens. Matter 15

Print publication: Issue 35 (3 September 2001)
Received 8 March 2001
Published 16 August 2001