排序方式: 共有15条查询结果,搜索用时 15 毫秒
11.
MR Eskildsen AB Abrahamsen PL Gammel DJ Bishop NH Andersen K Mortensen PC Canfield 《Pramana》2002,58(5-6):903-905
We compare the results of small angle neutron scattering on the flux line lattice (FLL) obtained in the borocarbide superconductor
LuNi2B2C with the applied field along the c- and a-axes. For H‖c the temperature dependence of the FLL structural phase transition from square to hexagonal symmetry was investigated. Above
10 K the transition onset field. H
2(T), rises sharply, bending away from H
c2(T) in contradiction to theoretical predictions of the two merging. For H‖a a first order FLL reorientation transition is observed at H
tr=3–3.5 kOe. Below H
tr the FLL nearest neighbor direction is parallel to the b-axis, and above H
tr to the c-axis. This transition cannot be explained using nonlocal corrections to the London model. 相似文献
12.
介绍了以铽(Tb)激活的高密度发光玻璃和光导纤维发光玻璃的特性。它应用在X射线实时成像系统中,可大大改善空间分辨能力。用它做的转换屏比一般晶粒状荧光物质做的厚得多,特别适合用于高能X射线实时成像系统 相似文献
13.
A.B. Beznosov V.V. Eremenko V.P. Gnezdilov 《Journal of magnetism and magnetic materials》1984,43(3):243-248
The single-crystal gadolinium dielectric permeability spectrum is investigated experimentally and theoretically in the frequency range 0.5 ? ω ?1 eV. The temperature dependence of d-f exchange resonance spectrum observed in the above range is interpreted. This is done in terms of the concept of intra-atomic light absorption and the magnetic order parameter dependence of the coherence degree of angular parts of quasi-bound 5d-electron wave functions. 相似文献
14.
E.L. Fertman A.B. Beznosov V.A. Desnenko L.N. Pal-Val P.P. Pal-Val D.D. Khalyavin 《Journal of magnetism and magnetic materials》2007
A coordinated temperature behavior of magnetic susceptibility and internal friction has been observed in the La2/3Ba1/3MnO3 manganite in the temperature region of the crystal phase separation 5–340 K. Stepwise temperature behavior of the susceptibility of the single crystal sample and corresponding singular behavior of the internal friction in the polycrystalline manganite have been found. These small-scale features of the temperature dependences of the susceptibility and the internal friction are considered to be a reflection of martensitic kinetics of the structural phase transformation R3¯c↔Imma in the 200 K temperature region. 相似文献
15.
Anatoly Beznosov Elena Fertman Vladimir Desnenko Marcela Kajňaková Alexander Feher 《Journal of magnetism and magnetic materials》2011,323(18-19):2380-2385
The low temperature specific heat and magnetic characteristics of Nd2/3Ca1/3MnO3 perovskite are studied in a wide range of magnetic fields (up to 9 T). Temperature dependent specific heat data show a broadened Schottky-like anomaly below 20 K caused by splitting of the Nd3+ ions ground-state doublet in the effective molecular field Hex, determined by exchange interaction between Nd and Mn spin systems supplemented by an applied external magnetic field. Existence of the splitting at zero magnetic field and expressed field dependence is the evidence of a strong exchange coupling between Nd and Mn magnetic subsystems. The Nd-ions magnetic ordering leads to an additional contribution to the magnetic moment of the system below 30 K, producing anomalies of the magnetic loss and field-cooled and zero-field-cooled magnetizations. The observed broadened Schottky-like anomalies are fitted for each applied magnetic field by the sum of three Schottky functions. Applied magnetic field extends the anomaly region and shifts it to higher temperatures. Splitting of the higher crystal field Kramers doublets gives an additional contribution to the heat capacity in magnetic fields. The ground state doublet g-factors g|| and g⊥ were estimated to be 3.4 and 2.2, respectively, and Hex was estimated to be 9 T. The Nd3+ ions magnetic moment estimated from the magnetization data agrees with the value obtained from the specific heat data. 相似文献