Magnetic percolation and inequivalence of Fe sites in YFexCo2−x (x = 0.03 and 1) Laves phase compounds

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2015, Vol.118 (4), p.1273-1277
• Main Authors: Śniadecki, Z., Kopcewicz, M., Pierunek, N., Idzikowski, B.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-014-8829-x

YCo 2 compound is an exchange-enhanced Pauli paramagnet on the verge of being magnetic. Topological or chemical disorder can induce in it ferromagnetic long-range ordering. The influence of Fe substitution and quenched-in topological disorder on the magnetic properties of YFe 0.03 Co 1.97 and YFeCo is studied. Structural and magnetic properties of these compounds are analyzed by means of X-ray diffraction, vibrating sample magnetometry, Mössbauer spectroscopy and AC magnetic susceptibility measurements. All samples crystallize in cubic MgCu 2 -type phase with lattice constant changing from 7.223 Å for YCo 2 through 7.221 Å for YFe 0.03 Co 1.97 to 7.313 Å for YFeCo. Fe atoms are responsible for stabilization of magnetic moments on Co, and mictomagnetism is observed in YFe 0.03 Co 1.97 sample. Upon further substitution, as in YFeCo, long-range ordering appears. The Mössbauer spectra permitted distinction between two magnetically inequivalent Fe sites, as reported earlier for YFe 2 .