Influence of grain boundary energy on the nucleation of complexion transitions

To test the effect of grain boundary energy on the nucleation of a transition from a low mobility to a high mobility grain boundary complexion, polycrystalline yttria-doped alumina was sandwiched between two single crystals of sapphire. Thermal groove measurements showed that the distribution of grain boundary energies at the single crystal–polycrystal interface is biased by the single crystal orientation. When annealed above the critical temperature for the complexion transition, the high mobility complexion preferentially nucleated at the higher energy interface.