Magnetic Characterization and Low-Temperature Heat Transport Properties of the Orthoferrites <italic>R</italic>FeO<sub>3</sub> (<inline-formula> <tex-math notation="LaTeX">$R =$ </tex-math></inline-formula> Rare Earth) Single Crystals

Abstract

Orthoferrites RFeO 3 (except R=Y, La and Lu) possess two sets of magnetic sublattice, that is, Fe3+ sub-system and R3+ sub-system. Magnetic properties and interactions between the two sub-systems including Fe-Fe, R-Fe, and R-R interactions depend on external parameters, such as temperature, magnetic field, etc.[1-3] So real magnetic materials can exhibt rich low temperature characteristics. We have successfully grown the orthoferrites RFeO 3 (R = Dy, Ho and Y) and Ho 1−x Y x FeO 3 (x = 0.1 and 0.3) by the floating zone technique using a four-mirror image furnace. The halogen lamp power and crystal growth atmosphere were identified to be the most important parameters. High-quality single crystals have been demonstrated by the X-ray diffraction data and X-ray Laue photograph. The magnetic transitions with decreasing temperature and the field-induced magnetic phase transitions in RFeO 3 for the rare earth ions and Fe3+ can be characterized by low-temperature magnetization and specific heat measurements. In addition, we report the low-temperature heat transport measurements of these orthoferrites single crystals to probe the magnetic properties and find that they show strong magnetic field dependence. The characteristic fields have a good correspondence with some transformations of the magnetic structure. These special behaviors demonstrate the magnetic field-induced transitions of the Fe3+ and R3+ spin structure.