Wu H.,Key Laboratory of Soft Chemistry Functional Materials |
Wu H.,Nanjing University of Science and Technology |
Qian Y.,Key Laboratory of Soft Chemistry Functional Materials |
Qian Y.,Nanjing University of Science and Technology |
And 8 more authors.
Physica B: Condensed Matter | Year: 2011
Our density functional theory calculations show that the origin of the stability of the Cu3 oxide, LaCu3Fe4O 12, is the strong hybridization interaction between LaOCu, which also suppresses structural symmetry change with changing temperature. From low-temperature antiferromagnetism to high-temperature paramagnetism, each Fe ion loses 0.34 electron and each Cu ion gets 0.45 electron, while the charges of La and O ions do not change. Additionally, each type of ion has the same total charge. The Coulomb attractive force between FeOFe at high temperature is stronger than that at low temperature, driving a large negative thermal expansion. © 2011 Elsevier B.V.