The infrared reflectance spectrum up to 2500cm^-1 for heavily overdoped T1-2201 at 300 K has been analysed under the semiclassical approximation. In this approach, we use two independent sets of parameters to fit the ...The infrared reflectance spectrum up to 2500cm^-1 for heavily overdoped T1-2201 at 300 K has been analysed under the semiclassical approximation. In this approach, we use two independent sets of parameters to fit the reflectance: the momentum-dependent Fermi velocity vk and the momentum-dependent scattering rate τ^-1 (εk ). Unlike the case at optimal doping in which the transport properties are dominated by the nodal quasi-particles (QPs), both the lifetime and the Fermi velocity of the QPs in the antinodal region near the Fermi surface increase remarkably for the heavily overdoped samples. Our fitting results indicate that the antinodal QPs tend to dominate the transport properties in heavily overdoped high-Tc cuprates.展开更多
The nonmagnetic element Ca-doped LiNbO3 films were prepared on Si(111) substrates by radio frequency(RF) magnetron sputtering technique. X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) indicate that t...The nonmagnetic element Ca-doped LiNbO3 films were prepared on Si(111) substrates by radio frequency(RF) magnetron sputtering technique. X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) indicate that the Ca atoms enter the LiNbO3 lattice in the form of Ca2+ ions. Superconducting quantum interference device(SQUID) results show that the Ca-doped LiNbO3 films have room-temperature ferromagnetism and a maximum saturation magnetization of 4800 A/m at the 3% of Ca atom doping concentration. The room temperature ferromagnetism of the Ca-doped LiNbO3 films can be attributed to the occurrence of vacancies due to Ca doping and is the intrinsic property.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10704054, the Tianjin High School Develop- ment Foundation for Science and Technology under Grant No 20060406, and Tianjin Key Laboratory for Photoelectric Materials and Devices.
文摘The infrared reflectance spectrum up to 2500cm^-1 for heavily overdoped T1-2201 at 300 K has been analysed under the semiclassical approximation. In this approach, we use two independent sets of parameters to fit the reflectance: the momentum-dependent Fermi velocity vk and the momentum-dependent scattering rate τ^-1 (εk ). Unlike the case at optimal doping in which the transport properties are dominated by the nodal quasi-particles (QPs), both the lifetime and the Fermi velocity of the QPs in the antinodal region near the Fermi surface increase remarkably for the heavily overdoped samples. Our fitting results indicate that the antinodal QPs tend to dominate the transport properties in heavily overdoped high-Tc cuprates.
基金supported by the National Natural Science Foundation of China(Nos.11174217 and 10904110)
文摘The nonmagnetic element Ca-doped LiNbO3 films were prepared on Si(111) substrates by radio frequency(RF) magnetron sputtering technique. X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) indicate that the Ca atoms enter the LiNbO3 lattice in the form of Ca2+ ions. Superconducting quantum interference device(SQUID) results show that the Ca-doped LiNbO3 films have room-temperature ferromagnetism and a maximum saturation magnetization of 4800 A/m at the 3% of Ca atom doping concentration. The room temperature ferromagnetism of the Ca-doped LiNbO3 films can be attributed to the occurrence of vacancies due to Ca doping and is the intrinsic property.