Spin Peltier effect and its length scale in Pt/YIG system at high temperatures

The temperature and yttrium-iron-garnet (YIG) thickness dependences of the spin Peltier effect (SPE) have been investigated using a Pt/YIG junction system at temperatures ranging from room temperature to the Curie temperature of YIG by the lock-in thermography method. By analyzing the YIG thickness dependence using an exponential decay model, the characteristic length of SPE in YIG is estimated to be 0.9 $\mu$m near room temperature and almost constant even near the Curie temperature. The high-temperature behavior of SPE is clearly different from that of the spin Seebeck effect, providing a clue for microscopically understanding the reciprocal relation between them.