Magnetic and crystallographic properties of Gd5Sb0.5Ge3.5 were investigated using dc magnetization, ac magnetic susceptibility, and heat capacity of an oriented single crystal, combined with temperature and magnetic field dependent x-ray powder diffraction. The compound undergoes an unusual magnetostructural transition at 40 K and a nonmagnetic second-order transition around 63 K. The detailed ...

Band theory predicts both K3C60 and K4C60 to be metals; various experimental probes show that while K3C60 is indeed metallic, K4C60 appears to be insulating. The standard view of this apparent failure of the single-particle picture is that electron correlation is predominant. We describe an alternative scenario, motivated on theoretical grounds, which invokes a spinor charge-density-wave state ...

Research Institute for Computational Sciences (RICS), National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 Research Center for Integrated Science (RCIS), Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, Ishikawa 923-1292 Creative Research Initiative ’Sousei’ (CRIS), Hokkaido University, Sapporo 001-0021 ...

In this paper a resonant tunnelling quantum well infrared photodetector (RT-QWIP) is discussed. Each period of this photodetector structure comprises of a resonant tunnelling structure (AlAs/AlGaAs/AlAs) nearby a quantum well (AlGaAs/GaAs). In this photodetector, photocurrent is produced when an electron makes a transition from the ground state of the well to an excited state which is coupled t...