The observation of spin reorientation phase transition in Sm1-x Erx FeO3

Through the observation of magnetic resonance modes by terahertz time domain spectroscopy (THz-TDS) at the various temperature, we succeeded in observing spin reorientation phase transition (SRPT) which occurs at 310 K for Sm
_0.7
Er
_0.3
FeO
₃
single crystals. Furthermore, THz-pump and optical-Faraday-rotation measurement was introduced and the weak F-mode signals were successfully observed just below SRPT temperature.