检索结果-南通市图书馆

specific heat of the non-centrosymmetric superconductor Re_3 W

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2009年第2期18卷 704-708页

作者：闫静单磊罗强汪卫华闻海虎 National Laboratory for Superconductivity Institute of Physics and Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences

The alloys of non-centrosymmetric superconductor, Re3W, which were reported to have an ^-Mn structure [P. Greenfield and P. A. Beck, J. Metals, N. Y. 8, 265 （1959）] with Tc = 9K, are prepared by arc melting. The values of ac susceptibility and the low-temperature specific heat of these alloys are measured. It is found that there are two superconducting phases coexisting in the samples with Tc1 ≈ 9 K and Tc2 ≈ 7K, which are both non-centrosymmetric in structure as reported previously. By analysing the specific heat data measured in various magnetic fields down to a temperature of 1.8 K, we find that the absence of the inversion symmetry does not lead to an obvious deviation from an s-wave pairing symmetry in Re3W.

关键词： ReaW non-centrosymmetric superconductivity specific heat

Linear magnetoresistance and structural distortion in layered SrCu_(4-x)P_(2) single crystals

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第1期33卷 591-594页

作者：聂勇陈正韦文森李慧杰张勇梅明王园园宋文海宋东升王钊胜朱相德宁伟田明亮 Anhui Key Laboratory of Low-energy Quantum Materials and Devices High Magnetic Field LaboratoryHFIPSChinese Academy of SciencesHefei 230031China Department of Physics University of Science and Technology of ChinaHefei 230026China Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China Information Materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China School of Physics Anhui UniversityHefei 230601China

We report a systematic study on layered metal SrCu_(4-x)P_(2) single crystals via transport, magnetization, thermodynamic measurements and structural characterization. We find that the crystals show large linear magnetoresistance without any sign of saturation with a magnetic field up to 30T. We also observe a phase transition with significant anomalies in resistivity and heat capacity at T_(p)~140 K. Thermal expansion measurement reveals a subtle lattice parameter variation near Tp, i.e.,?L_(c)/L_(c)~0.062%. The structural characterization confines that there is no structure transition below and above T_(p). All these results suggest that the nonmagnetic transition of SrCu_(4-x)P_(2) could be associated with structural distortion.

关键词： linear magnetoresistance thermal expansion specific heat structural distortion

Low temperature specific heat of 12442-type KCa2Fe4As4F2 single crystals

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2020年第9期63卷 99-104页

作者： Teng Wang JiaNan Chu JiaXin Feng LingLing Wang XuGuang Xu Wei Li HaiHu Wen XiaoSong Liu Gang Mu State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China CAS Center for Excellence in Superconducting Electronics(CENSE) Shanghai 200050China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Surface Physics and Department of Physics Fudan UniversityShanghai 200433China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China Center for Superconducting Physics and Materials National Laboratory of Solid State Microstructures and Department of PhysicsNanjing UniversityNanjing 210093China

Low-temperature specific heat(SH)is measured for the 12442-type KCa2Fe4As4F2 single crystal under different magnetic fields.A clear SH jump with the height of?C/T|Tc=130 mJ mol-1 K-2 is observed at the superconducting transition temperature Tc.It is found that the electronic SH coefficient?γ(H)quickly increases when the field is in the low-field region below 3T and then considerably slows down the increase with a further increase in the field,which indicates a rather strong anisotropy or multi-gap feature with a small minimum in the superconducting gap(s).The temperature-dependent SH data indicate the presence of the T2 term,which supplies further information and supports the picture with a line-nodal gap structure.Moreover,the onset point of the SH transition remains almost unchanged under the field as high as 9 T,which is similar to that observed in cuprates,and places this system in the middle between the BCS limit and the Bose-Einstein condensation.

关键词： specific heat gap structure KCa2Fe4As4F2

Quasiparticle density of states of 2H-NbSe_2 single crystals revealed by low-temperature specific heat measurements according to a two-component model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2008年第6期17卷 2229-2235页

作者：闫静单磊王越肖志力闻海虎 National Laboratory for Superconductivity Institute of Physics and Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences Materials Science Division Argonne National Laboratory Argonne Illinois 60439 USA Department of Physics Northern Illinois University DeKalb Illinois 60115 USA

Low-temperature specific heat in a dichalcogenide superconductor 2H-NbSe2 is measured in various magnetic fields. It is found that the specific heat can be described very well by a simple model concerning two components corresponding to vortex normal core and ambient superconducting region, separately. For calculating the specific heat outside the vortex core region, we use the Bardeen-Cooper Schrieffer （BCS） formalism under the assumption of a narrow distribution of the superconducting gaps. The field-dependent vortex core size in the mixed state of 2H-NbSe2, determined by using this model, can explain the nonlinear field dependence of specific heat coefficient γ（H）, which is in good agreement with the previous experimental results and more formal calculations. With the high-temperature specific heat data, we can find that, in the multi-band superconductor 2H-NbSe2, the recovered density of states （or Fermi surface） below Tc under a magnetic field seems not to be gapped again by the charge density wave （CDW） gap, which suggests that the superconducting gap and the CDW gap may open on different Fermi surface sheets.

关键词： 2H-NbSe2 charge density wave superconductivity specific heat

Magnetic and specific heat studies of the frustrated Er_2Mn_2O_7 compound

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2013年第1期31卷 54-59页

作者： N.Ben Amor M.Bejar E.Dhahri M.A.Valente P.Lachkar E.K.Hlil Laboratory of Applied Physics Faculty of Sciences of SfaxBP 1171University of Sfax I3N and Physics Department University of Aveiro MCMF Néel InstitutCNRS25 avenue des MartyrsBuilding FBP 16638042 Grenoble cedex 9France MCBT Institut NéelCNRS25 avenue des MartyrsBuilding EBP 16638042 Grenoble cedex 9France

A new ErzMn207 compound was synthesized by the ceramic method and its crystal structure was characterized LJsing powder X-ray diffraction （XRD） and observed by scanning electron microscopy （SEM）. The magnetic properties were investigated using a BS2 magnetometer and the heat capacity was studied using a quantum design （PPMS）. The structural study revealed that this compound was monophasic and crystallized in the monoclinic system with the P2/M space group. Magnetization measurements were carried out in the temperature range of 1.8-200 K under an applied magnetic field of 0.05 T. A crossover from a room temperature para- magnetic phase to an antiferromagnetic one at low temperature was detected from the magnetic study. The magnetic susceptibility, in the paramagnetic region above 40 K, was found to present a simple Curie-Weiss type behavior. From the specific heat （G,） measurements in magnetic fields up to 5 T, we noted the presence of a wide peak characteristic of a second order magneto-structural transition.

关键词： magnetic frustration magnetic phase transition specific heat rare earths

Effects of anisotropy and magnetic fields on the specific heat of a quasi-two-dimensional Boltzmann gas in an elliptical parabolic quantum dot

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2012年第7期21卷 201-206页

作者：翟智远李玉奇潘孝胤 Department of Physics Ningbo University

We investigate the effects due to anisotropy and magnetic field interaction for a quasi-two-dimensional Boltzmann gas in an elliptical parabolic quantum dot. The specific heat is studied with varying temperature, anisotropy, and magnetic field strength. The cases without and with the inclusion of the spin Zeeman interaction are considered.

关键词： specific heat Zeeman interaction anisotropy harmonic oscillator

specific heat of a PIN-PMN-PT single-crystal up to 500 K

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Dielectrics 2017年第5期7卷 32-35页

作者： S.Grabovsky I.Shnaidshtein J.Przeslawski Zhenrong Li Zhuo Xu B.Strukov Faculty of Physics Lomonosov Moscow State University Moscow 119991Russia Institute of Experimental Physics Wroclaw University 50-204 WroclawPoland Electronic Materials Research Laboratory Key Laboratory of the Ministry of Education and International Center for Dielectric Research Xi'an Jiao tong University Xi'an 710049P.R.China

The temperature dependence of the specific heat of the single crystal Pb(In_(0.5)Nb_(0.5))O_(3)-Pb(Mg_(1/3)Nb_(2/3))O_(3)-PbTiO_(3)(PIN-PMN-PT)was obtained at 80–500 K by means of ac-calorimetry,and comparison with the calorimetric data for PMN was made,allowing one to determine absolute values of the specific heat of PIN-PMN-PT.For the high-temperature region(T>200 K),the background heat capacity was calculated,the anomalies of the heat capacity for both compounds were determined,and the hump of the temperature dependence of specific heat PIN-PMN-PT was detected for the first time.

关键词： Ferroelectricity perovskites specific heat relaxors

Theory of specific heat of vortex liquid of high T_c superconductors

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2016年第10期25卷 398-402页

作者：白晨迟诚王江帆 Institute of Theoretical Physics School of Physics Peking University

Superconducting thermal fluctuation(STF) plays an important role in both thermodynamic and transport properties in the vortex liquid phase of high Tsuperconductors.It was widely observed in the vicinity of the critical transition temperature.In the framework of Ginz burg-Landau-La wrence-Doniach theory in magnetic field,a self-consistent analysis of STF including all Landau levels is given.Besides that,we calculate the contribution of STF to specific heat in vortex liquid phase for high Tcuprate superconductors,and the fitting results are in good agreement with experimental data.

关键词： superconducting thermal fluctuation vortex liquid self-consistent approximation specific heat

Prediction of Thermal Conductivity and specific heat of Native Maize Starch and Comparison with HMT Treated Starch

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2019年第6期7卷 535-546页

作者： Aklouche Leila Monteau Jean-Yves Rezzoug Sid-Ahmed Maugard Thierry Guihard Luc Cohendoz Stephane Maache-Rezzoug Zoulikha LaSIE UMR CNRS 7356University of La RochelleAvenue Michel Crépeau17042 La RochelleFrance GEPEA UMR CNRS 6144ONIRISRue de la Géraudière44322 NantesFrance LIENSs UMR CNRS 7266 Universitéde La RochelleFrance

specific heat(Cp)and effective thermal conductivity(λ)of native maize starch(NS)were measured by DSC and transient heat transfer method,respectively,at different moisture contents and temperatures.The dependency of temperature(T)and moisture content(W)on the two parameters were investigated.The thermophysical properties of treated starch(TS)by four hydrothermal processes(RP-HMT,IV-HMT,DV-HMT and FV-HMT)were measured and compared to native strach.Hydrothermal treatments were performed at 3 bars(133°C)for 10 min.For Cp andλmeasurements,moisture content varied for NS from 5 to 21.5%d.***.and from 8.8 to 25%d.b.,respectively,and was fixed at 6%d.***.for TS.Empirical models were developed to specific heat and effective thermal conductivity,using a multiple regression algorithm with subsequent statistical analysis.The proposed models for NS based on T and W predict Cp andλwith a mean absolute error of 3.5%and 1.3%,respectively.Large differences in specific heat were observed between TS and NS.In a temperature range of 40 to 160°C,Cp values varied from 1.964 to 2.699 for NS and 1.380 to 2.085(J.g-1.°C-1)for TS.In contrast,the conductivity of NS was almost identical to that of treated starch by FV-HMT,followed in an increasing order by those treated by DV-HMT,RP-HMT,and IV-HM processes.

关键词： Starch HMT treatment specific heat effective thermal conductivity