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Title: Magnetization-free measurements of spin orientations in orthoferrites using terahertz time domain spectroscopy

The spin orientation during spin reorientation phase transition in a weak ferromagnetic orthoferrite Dy{sub x}Er{sub 1−x}FeO{sub 3} (x = 0.7) has been studied by using terahertz time domain spectroscopy under zero and weak external magnetic fields. The spin orientation angle was deduced from the ratio of the absorption intensity of quasi-ferromagnetic and quasi-antiferromagnetic modes, which appear around 0.25 and 0.4 THz, respectively. Between 11.4 and 17.9 K, this material showed a rotation-type reorientation transition rather than Morin-type transition. The temperature and magnetic field dependence of the orientation angle of the magnetic moment was found to follow a simple model assuming a linear temperature dependence of the anisotropy parameter. It has been also shown that this method is insensitive to the domain structure with opposite polarity and that it allows measurement without macroscopic magnetization.
Authors:
; ; ;  [1]
  1. Laser and Synchrotron Research Center, Institute for Solid State Physics, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8581 (Japan)
Publication Date:
OSTI Identifier:
22486383
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; ANISOTROPY; ANTIFERROMAGNETISM; DOMAIN STRUCTURE; MAGNETIC FIELDS; MAGNETIC MOMENTS; MAGNETIZATION; PHASE TRANSFORMATIONS; SPECTROSCOPY; SPIN; SPIN ORIENTATION; TEMPERATURE DEPENDENCE