SPIN-GLASS-LIKE MAGNETIC-PROPERTIES FOR RFE10MO2 COMPOUNDS (R=Y OR LU) WITH THE THMN12-TYPE STRUCTURE

dc and ac magnetic measurements combined with Mossbauer spectroscopy have been used to study the evolution of magnetic order below the critical temperature T(c) in polycrystalline powders of the intermetallic compounds YFe10Mo2 and LuFe10Mo2. Irreversibility of the dc thermomagnetic curves after zero-field-cooling (ZFC) and field-cooling (FC) processes has been observed. A hysteresis loop has been detected for both compounds at 4.5 K and a shifting of the loop after FC has been observed in LuFe10Mo2. Strong spin-relaxation effects were recorded in Fe-57 Mossbauer absorption spectra in temperatures well below the T(c) = 360 and 260 K for R = Y and Lu alloys, respectively. Furthermore, a number of magnetic properties common to conventional spin glasses and true ferromagnets has been revealed, which suggest the existence of a spin-glass-like magnetic phase below T(c).