1303-13-5Relevant articles and documents
Ge concentration in regrown GaAs for ohmic contacts
Kim,Holloway,Kenik
, p. 3835 - 3837 (1997)
Dissociation and solid phase epitaxial regrowth of GaAs in Ti/Ge/Ni/GaAs were investigated using the transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS) of x-rays with spatial resolution approaching 2 nm. A ternary Ni2.4GaAs phase, ～ 130 nm thick, was formed by 300°C in situ anneals of 65 nm Ni film on GaAs. After this in situ anneal, films of 30 nm Ge and 20 nm Ti were deposited in sequence. The EDS analysis showed that Ni2.4GaAs transformed into Ni-As and Ni-Ga binaries after annealing at 500°C for 5 min, while ～ 30 nm of GaAs regrew by solid phase epitaxial regrowth from decomposition of the binary phases. High spatial resolution microanalysis allowed detection of ～ 1 X 1020 cm-3 Ge in the regrown GaAs. This confirms that Ge is incorporated into GaAs during regrowth for ohmic contact formation.
Structure and Transport Properties in Itinerant Antiferromagnet RE2(Ni1-xCu x)5As3O2 (RE = Ce, Sm)
Chen, Xu,Guo, Jian-Gang,Gong, Chunsheng,Cheng, Erjian,Song, Yanpeng,Ying, Tianping,Deng, Jun,Li, Shiyan,Chen, Xiaolong
, p. 2770 - 2776 (2019/02/28)
We report the crystal structure and physical properties of two Ni5As3-based compounds RE2Ni5As3O2 (RE = Ce, Sm). The former exhibits structural phase transition from tetragonal (space group I4/mmm, 139) to orthorhombic (space group Immm, 71) symmetry at 230 K, while the latter undergoes a charge-density-wave-like structural distortion with abrupt change of Ni-As bond length. Both compounds show antiferromagnetic transitions due to RE3+ ions ordering at 4.4 and 3.4 K, accompanying with the large enhancement of Sommerfeld coefficients comparing to the nonmagnetic La analogue. Although the Cu substitution for Ni induces structural anomalies and suppression of structural transition like the behaviors in La/Pr/Nd analogues, the superconductivity is not observed in both Cu-doped RE2Ni5As3O2 (RE = Ce, Sm) above 0.25 K. Our structural refinements reveal that the lacking of superconductivity in RE2(Ni1-xCux)5As3O2 might relate to the anomalous increase of As height, h1.
Nickel-based layered superconductor, LaNiOAs
Watanabe, Takumi,Yanagi, Hiroshi,Kamihara, Yoichi,Kamiya, Toshio,Hirano, Masahiro,Hosono, Hideo
, p. 2117 - 2120 (2009/02/04)
Rietveld analysis of the powder X-ray diffraction of a new layered oxyarsenide, LaNiOAs, which was synthesized by solid-state reactions, revealed that LaNiOAs belongs to the tetragonal ZrCuSiAs-type structure (P4/nmm) and is composed of alternating stacks of La-O and Ni-As layers. The electrical and magnetic measurements demonstrated that LaNiOAs exhibits a superconducting transition at 2.4 K, and above this, LaNiOAs shows metallic conduction and Pauli paramagnetism. The diamagnetic susceptibility measured at 1.8 K corresponded to ～20percent of perfect diamagnetic susceptibility, substantiating that LaNiOAs is a bulk superconductor.
