Spin reorientation in the Er2−xFe14+2xSi3 single crystal studied by the Fe57 Mössbauer spectroscopy and magnetic measurements

Abstract

Spin reorientation in the single crystal of Er2−xFe14+2xSi3 with x=0.25(5) has been studied in the temperature range of 4–300K by means of the magnetic measurements and Mössbauer spectroscopy on Fe57 by using the 14.41keV resonant transition. The bulk magnetic moment has been measured versus applied field up to ±8.9T along the c axis of the P63∕mmc cell at 4K. The hysteresis loop has been measured at 300K for the external field applied along the c axis. The bulk moment has been measured versus temperature in the moderate external field of 0.1T applied along the c axis. The ac susceptibility has been measured for several frequencies and amplitudes of the ac field applied along the c axis versus temperature either in the null external field or in the external field of 0.1T along the c axis. Mössbauer measurements were performed versus temperature on the powder sample and single crystal with the radiation beam oriented along the c axis. The spin reorientation from the [a−b] plane onto the c axis occurs for all iron sublattices except for iron dumbbells substituting erbium (2b) in the temperature range of 130–80K due to the domain flip mechanism. The reorientation is less perfect for the sublattices containing silicon, i.e., (12j) and (12k). A gradual second reorientation of the above sublattices occurs below 50K leading to the partial recovery of the high temperature spin structure. Iron dumbbells substituting erbium do not participate in this recovery. For temperatures below 20K, some dipolar contribution to the iron field on (4f) dumbbell sites is seen. It is probably induced by the reorientation of the erbium magnetic moments.