“…[21][22][23][24][25] The widths of the domain walls in LSGM are in the range of 4 -20 nm, 26,27 and the local atomic structure of the domain walls differs from that of the domains. 28,29 LSGM undergoes three phase transitions: ͑i͒ orthorhombic to monoclinic ͑Imma-I2/a͒ around 550 K, ͑ii͒ monoclinic to trigonal ͑I2/a-R3c͒ around 690 K, and ͑iii͒ trigonal to trigonal ͑R3c-R3c͒ around 870 K. 21,22 The twin boundary relates a domain to another by a symmetry operation at these phase transitions. 21,22 Since a small amount of experimental knowledge on the ionic transport properties in the twin structures is available, it would be interesting to elucidate the electric conduction in these lattice structures.…”