排序方式: 共有44条查询结果,搜索用时 15 毫秒
21.
V. I. Gatalskaya M. Baran R. Szymczak H. Szymczak S. N. Barilo G. L. Bychkov S. V. Shiryaev 《Physics of the Solid State》2007,49(1):107-112
The magnetic characteristics of a twin-free EuBaCo2O5.5 single crystal were studied. It is shown that Co ions exhibit an Ising-type behavior with an easy axis directed along the a axis in the temperature range from 2 K to T c (250 K). As the temperature decreases from 300 K, a number of magnetic phase transitions occur under magnetic fields H ∥ a. In the range where antiferromagnetic ordering of Co3+ ions exists, metamagnetic transitions were observed to occur in fields whose values were dependent on temperature. The strengths of competing interactions in the crystal are estimated. 相似文献
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Ki Hwan Bae 《中国化学快报》2009,20(11):1321-1323
Phytochemical study on the BuOH-soluble fraction of the stem bark of Populus davidiana resulted in the isolation of a new salicin derivative(1),named davidianoside.The structure was elucidated on the basis of extensive physicochemical and spectroscopic analyses. 相似文献
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From the transport studies in the bilayer manganites LaSr2−x
Ca
x
Mn2O7, we have found the variable-range hopping model proposed by Viret et al to be inadequate to describe the transport of charge in these materials. The polarons appear to hop to their nearest neighbors
with an activation energy, which in part is dependent on the magnetic interactions in the lattice. 相似文献
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R. Szymczak M. Baran J. Fink-Finowicki B. Krzymanska P. Aleshkevych H. Szymczak S.N. Barilo G.L. Bychkov S.V. Shiryaev 《Journal of Non》2008,354(35-39):4186-4188
The effect of nonmagnetic Mg2+ and magnetic Co2+ doping in Kagome staircase compounds was investigated using DC magnetic susceptibility. The main effect of doping is to change effective anisotropy of the Ni3V2O8 and Co3V2O8 crystals. It has a considerable effect on magnetic field induced phase transitions in both kinds of crystals. The doping has also an effect on the Dzyaloshinskii–Moriya exchange interactions. In some cases the doping enhances this interaction while in another it suppresses it completely. 相似文献
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W. Henggeler T. Chattopadhyay B. Roessli D. I. Zhigunov S. N. Barilo A. Furrer 《Zeitschrift für Physik B Condensed Matter》1995,99(1):465-467
We performed inelastic neutron scattering experiments to determine the dispersion of the Г
6
(1)
-Г
6
(2)
crystal field excitation in Nd2CuO4. Our results can be very well described within the random phase approximation model. This allows a direct determination of
the exchange coupling constants between the Nd ions. The superexchange interactions mediated by the oxygen and copper-oxygen
layers are determined to be significantly stronger than the in-plane exchange between the Nd ions. 相似文献
27.
H.J. Kang Y.S. Lee J.W. Lynn S.V. Shiryaev S.N. Barilo 《Physica C: Superconductivity and its Applications》2011,471(9-10):303-307
We have observed a softening of phonons and a structural phase transition in a superconducting Ba0.59K0.41BiO3 (Tc = 31 K) single crystal using elastic and inelastic neutron scattering measurements. The soft phonon occurs for the [1 1 1] transverse acoustic mode at the zone boundary. The phonon energies in this vicinity are found to continuously decrease with decreasing temperature from above room temperature. This softening stops at a temperature close to Ts, where a structural phase transition from cubic to tetragonal symmetry occurs. The overall results are consistent with previous data that reported phonon softening and a (0.5, 0.5, 0.5) type superstructure in several Ba1?xKxBiO3 systems. However, we also find weaker (0.5, 0.5, 0) type superstructure peaks that reveal an additional component to the modulation. No significant change related to the superconductivity was observed for these soft phonon energies or linewidths. 相似文献
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MVN Murthy Urjit A Yajnik KRS Balaji G Bhattacharyya Amol Dighe Shashikant Dugad ND Hari Dass PK Kabir Kamales Kar D Indumathi John G Learned Debasish Majumdar NK Mondal MVN Murthy SN Nayak Sandip Pakvasa Amitava Raychaudhuri RS Raghavan G Rajasekaran R Ramachandran Alak K Ray Asim K Ray Saurabh Rindani HS Sharatchandra Rahul Sinha Nita Sinha S Umasankar Urjit A Yajnik 《Pramana》2000,55(1-2):347-355
We have identified some important and worthwhile physics opportunities with a possible neutrino detector located in India.
Particular emphasis is placed on the geographical advantage with a stress on the complimentary aspects with respect to other
neutrino detectors already in operation. 相似文献