Temperature dependence of rare-earth orthoferrite properties relevant to propagating domain device applications

The behavior of stable cylindrical domains, under variations in temperature, has been studied in a number of the rare-earth orthoferrites from the point of view of the need for temperature control when these materials are used in propagating domain devices. Fractional changes in domain diameter from -0.60 percent/°K in YFeO3to -2.71 percent/°K in a mixed orthoferrite, Sm0.55Tb0.45FeO3have been observed at 300°K. The mixed orthoferrites in which the region of reorientation of the magnetization is near room temperature provide domain diameters of 25 μm or less, making possible a high bit density. However, rapidly varying wall energy in this region leads to a substantial temperature dependence of domain size. In the YFeO3, the wall energy is almost constant from 77 to 350°K.