共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
H. Fujishita S. Murakami N. Nakamura Y. Kanou H. Okamoto 《Solid State Communications》2008,145(5-6):246-249
The lattice parameters of La1.85Sr0.15CuO4 were measured by an x-ray Rietveld method between 15 K and room temperature. A change in a lattice parameter could be detected at superconducting phase transition. It is pointed out, for the first time, that the change can be attributed to a spontaneous strain in the superconducting phase caused by coupling between a superconducting order parameter and the strain. 相似文献
3.
4.
The high-T
c
superconductor La1.85Sr0.15CuO4 was investigated by means of point contact and tunneling measurements on small-sized contacts. We find different values for the energy gap at different points of the samples. The ratio 2/k
B
T
c
ranges from about 3 to 6. For some point contacts we observe a clear signature of a supercurrent. Data for the temperature dependence of the critical current are presented. 相似文献
5.
采用溶胶凝胶结合多孔氧化铝硬模板约束的方法,成功制备出直径约30nm的La1.85Sr0.15CuO4纳米线阵列,用XRD与X-ray EDX测定了所制备纳米线的物相与成分;FE-SEM与TEM表征了其形貌特征;由HRTEM与SAKD测量分析了其微结构;磁化强度的测量结果表明样品具有L-30K的超导电性,比块材La1.85Sr0.15CuO4的Tc稍低.分析表明所制各的样品中存在一种α,b轴拉伸,c轴压缩的结构畸变,减弱了铜氧面内Cu3d和O2p轨道的杂化程度,减小了α,b面内的态密度,从而压制了体系的超导电性. 相似文献
6.
采用溶胶-凝胶结合多孔氧化铝硬模板约束的方法,成功制备出直径约30nm的La1.85Sr0.15CuO4纳米线阵列,用XRD与X-ray EDX测定了所制备纳米线的物相与成分;FE-SEM与TEM表征了其形貌特征;由HRTEM与SAED测量分析了其微结构;磁化强度的测量结果表明样品具有Tc= 30 K的超导电性,比块材La1.85Sr0.15CuO4的Tc稍低.分析表明所制备的样品中存在一种a,b轴拉伸,c轴压缩的结构畸变,减弱了铜氧面内Cu3d和O2p轨道的杂化程度,减小了a,b面内的态密度,从而压制了体系的超导电性. 相似文献
7.
《Physics letters. A》1987,122(1):61-63
The stability of a shielding current in a hollow cylinder of La1.85Sr0.15CuO4 has been studied with a superconducting quantum interference device (SQUID). From the observed lack of decay of the current an upper limit of 3×10-17ω cm has been established on the resistivity at 4.2 K. 相似文献
8.
Low-energy spin excitations of La(1.85)Sr(0.15)Cu(1-y)Zn(y)O4 were studied by neutron scattering. In y=0.004, the incommensurate magnetic peaks show a well-defined "spin gap" below T(c). The magnetic signals at omega=3 meV decrease below T(c)=27 K for y=0.008, also suggesting the gap opening. At lower temperatures, however, the signal increases again, implying a novel in-gap spin state. In y=0.017, the spin gap vanishes and elastic magnetic peaks appear. These results clarify that doped Zn impurities induce the novel in-gap state, which becomes larger and more static with increasing Zn. 相似文献
9.
10.
利用脉冲激光法研究了在(100)SrTiO3(STO)、(100)LaAlO3(LAO)和(100)Y-ZrO2(YSZ)衬底上外延生长LaCuO4(LCO),La1.85Sr0.15CuO4(LSCO),Nd1.85Ce0.15CuO4(NCCO)和Pr2CuO4(PCO)薄膜的工艺技术。利用X光衍射仪检测了不同条件下制备的薄膜样品结构和取向。X射线衍结果表明,在事适的制膜条件下可以在这三种衬底 相似文献
11.
12.
13.
Karpinska K Cieplak MZ Guha S Malinowski A Skoskiewicz T Plesiewicz W Berkowski M Boyce B Lemberger TR Lindenfeld P 《Physical review letters》2000,84(1):155-158
Measurements of the resistivity, magnetoresistance, and penetration depth were made on films of La1.85Sr0.15CuO4, with up to 12 at. % of Zn substituted for the Cu. The results show that the quadratic temperature dependence of the inverse square of the penetration depth, indicative of d-wave superconductivity, is not affected by doping. The suppression of superconductivity leads to a metallic nonsuperconducting phase, as expected for a pairing mechanism related to spin fluctuations. The metal-insulator transition occurs in the vicinity of k(F)l approximately 1, and appears to be disorder driven, with the carrier concentration unaffected by doping. 相似文献
14.
L. S. Fomenko S. V. Lubenets V. S. Bobrov A. N. Izotov 《Physics of the Solid State》1998,40(3):453-457
The microhardness of La2CuO4 and La1.85Sr0.15CuO4 crystals is measured in the temperature range 81–292 K, and the influence of various factors on it is investigated. The thermal
activation parameters of the plastic deformation process in the vicinity of the indenter impression are estimated. The change
of the phase state of the compound La1.85Sr0.15CuO4 at the temperature T
0=180 K and the appearance of domain (twin) boundaries formed in the ferroelastic tetraortho transition are not seen in the
temperature dependence of the microhardness. The results of the study are compared with previously published results for YBa2CuO7−x
crystals.
Fiz. Tverd. Tela (St. Petersburg) 40, 493–497 (March 1998) 相似文献
15.
16.
《Solid State Communications》1987,62(6):383-385
We have measured the energy gap of a polycrystalline sample of La1.85Sr0.15CuO4 using far-infrared reflectance. The sample was prepared by sintering and has a superconducting transition at 36 ±1 K (mid point of a 2K wide region) both in resistance and magnetic susceptibility. The Meissner effect was incomplete and there was considerable absorption below the gap frequency in the superconducting state. The change in far infrared absorption on going to the superconducting state was fitted to the theory of Mattis and Bardeen, yielding an energy gap of (3.2 ± 0.3) kTc withTc= 36 K 相似文献
17.
18.
19.
《Solid State Communications》1987,63(7):657-659
We report the reflectance spectra of pressed powder samples of the high-temperature superconductor La1.85Sr0.15CuO4 and of La2CuO4 in the energy range beteween 30 meV and 6 eV. The spectrum of the superconducting compound differs remarkably from those of conventional metals. It shows a plasma edge in the near infrared with a plasma energy of ℏωp = 0.8 eV and optical phonons up to an energy of 90 meV. The optical results yield a very low carrier concentration of 1.7 x 1021cm3. 相似文献