Nonzero Spontaneous Magnetic Moment along the b-Axis and the 2-Fold Spin Reorientation Transition in a Er0.4Gd0.6FeO3 Single Crystal

Abstract

Single crystal Er0.4Gd0.6FeO3 (EGFO) was grown by optical floating-zone method. The magnetic properties at three crystallographic axes were investigated in detail. Two special magnetic characteristics were found in EGFO. One is that nonzero spontaneous magnetic moment along crystalline b-axis exists below ∼45 K. This phenomenon is unusual for most of rare-earth orthoferrites. Another one is that the special 2-fold spin reorientation transition was observed. Such a transition can be defined as Γ4 → Γ3 → Γ4, which is the result of the competitions of Er3+–Fe3+ and Gd3+–Fe3+ interactions with Fe3+–Fe3+ interaction at different temperature areas. In addition, the result of spin reorientation transition at different magnetic fields suggested that a magnetic field can modify the anisotropy interaction between rare-earth ions and Fe3+ ions. This work is meaningful for further studying the physical phenomenons in RFeO3 and their potential applications.