Dielectric characteristics of Ga doped TbMnO3

Low-frequency (0.1–200 kHz) dielectric properties of Tb1−xGaxMnO3 and TbGayMn1−yO3 (x, y = 0.05, 0.1, 0.2, 0.3, 0.4) ceramic composites, which were synthesized by conventional solid-state reaction, were investigated in the temperature range from 77 to 350 K. Both dielectric constants and loss tangent (tan δ) increase with increasing temperature and decrease with increasing frequency, respectively. Interestingly, the dielectric constants of Tb1−xGaxMnO3 are as large as that of the parent TbMnO3, while the loss tangent reduces remarkably and less than 1 at high frequencies. These improvements demonstrate that Ga doped TbMnO3 may have potential applications.

► Compared with TbGayMn1−yO3, Tb1−xGaxMnO3 samples have larger grains, which exhibit a larger dielectric constants and the advancing switching temperature.
► Both dielectric constants and loss tangent (tan δ) increase with increasing temperature and decrease with increasing frequency, respectively.
► The dielectric loss of Tb1−xGaxMnO3 is low (less than 1) in a wide temperature range even at room temperature.
► The curves of ɛ″ with frequency fall on a straight line at T > 210 K.