材料期刊网

It has been reported both experimentally and theoretically that the Ba(2+)-doping at the A-site of quantum paraelectric SrTiO(3) suppresses the quantum fluctuations by activating the ferroelectric mode, while the Ru(4+)-doping at the B-site plays the opposite role. For a double-impurity doped SrTiO(3), i. e., Sr(1-x)Ba(x)Ti(1-y)Ru(y)O(3), where the two types of opposite effects compete with each other, we propose an improved transverse-field Ising model in order to investigate the effect of the double-impurity doping on the quantum phase transitions and critical behaviors. The calculated quantum behavior is quite well consistent with experimental measurements. A linear relationship between the quantum critical doping concentrations for Ba(2+) and Ru(4+) is predicted, subsequently validated qualitatively by an anharmonic oscillator model. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3361080]