Premium
Tuning of conductive type and magnetic properties of Ca 3 Co 2 O 6 ceramics through Pb‐doping
Author(s) -
Song Jiyue,
Zhao Bangchuan,
Huang Yanan,
Qin Yanfeng,
Song Wenhai,
Sun Yuping
Publication year - 2017
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.14904
Subject(s) - doping , seebeck coefficient , materials science , electrical resistivity and conductivity , analytical chemistry (journal) , ferromagnetism , valence (chemistry) , hall effect , magnetization , ion , ceramic , condensed matter physics , chemistry , magnetic field , thermal conductivity , metallurgy , physics , optoelectronics , organic chemistry , chromatography , quantum mechanics , electrical engineering , composite material , engineering
The effect of Pb doping on structural, electrical, magnetic, and thermal transport properties of Ca 3− x Pb x Co 2 O 6 ( x =0‐0.3) ceramics has been investigated systemically. It is found that the substituted Pb‐ions have a mixed valence state of +2 and +4, and a small amount of Co 3+ ions will transfer into Co 2+ due to the substitution of Pb 4+ for Ca 2+ . The resistivity decreases monotonically with increasing Pb content, which is related to the variation in carrier concentration and the enhanced grain connectivity. The signs of both Hall coefficient and thermopower changed from positive to negative by a proper Pb doping, indicating the conductive type of Ca 3 Co 2 O 6 can be effectively tuned from p to n through the doping. The low‐temperature magnetization, the magnetic exchange coupling constant J and Weiss temperature θ decrease monotonically with the increase in Pb‐doping content, indicating the strength of the ferromagnetic interaction between adjacent high spin Co 3+ ions has been weakened due to the reduced magnetic correlation length in these Pb‐doped samples.