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 h ave been used to study the evolution of magnetic order below the criti cal temperature T(c) in polycrystalline powders of the intermetallic c ompounds YFe10Mo2 and LuFe10Mo2. Irreversibility of the dc thermomagne tic curves after zero-field-cooling (ZFC) and field-cooling (FC) proce sses has been observed. A hysteresis loop has been detected for both c ompounds at 4.5 K and a shifting of the loop after FC has been observe d 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 numbe r 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).