The temperature dependence of the domain structure in thulium orthoferrite
Abstract
The domain structure of thulium orthoferrite in the spontaneous spin-flip region of Fe3+ ions has been studied. The domain structure, which is a maze structure at room temperature, becomes a strip structure in the spin-flip region T2–T1 (T2 is the beginning and T1 is the end of the transition). As the temperature is raised from T1 the strip-domain structure is preserved up to roughly 150 °K, after which bubbles appear along with the strip structure. It is suggested that the observed change in the domain structure during the spin-flip phase transition is caused by the presence of a potential barrier between the strip and maze structures, owing to the difference of the magnetostatic energies of the two structures. The domain-wall energy σw(T) and the anisotropy constant K1 (T) are found as a function of the temperature from the temperature dependence of the period of the strip-domain structure.