相关论文: Ferromagnetic- and Superconducting-like Behavior o…
Effects related to the granularity of a La1.85Sr0.15CuO4 ceramic sample, synthesized by the solidstate reaction method, are presented. The superconducting transition exhibits a step-like behavior. Lowtemperature features of…
Hysteresis is more than just an interesting oddity, which occurs in materials with a first-order transition. It is a real obstacle on the path from existing lab-scale prototypes of magnetic refrigerators towards commercialization of this…
We show that some experimentally observed features of vortex matter in high temperature superconductors may be interpreted in simpler ways than it is usually done. In particular, we consider magnetic flux creep at low temperatures as well…
Ferromagnetic behaviour has been observed experimentally for the first time in nanostructured Manganese. Ultrathin ($\sim$ 0.6 nm) Manganese nanosheets have been synthesized inside the two dimensional channels of sol-gel derived Na-4 mica.…
Pump-probe experiments and polarizing microscopy are applied to examine temperature and heat flow in metallic magnetic superlattices on glass substrates. A model of heat diffusion in thin layers for cylindrical symmetry, equivalent to the…
The magnetic properties of a series of YBa2Cu3O7-x/La2/3Ca1/3MnO3 (YBCO/LC1/3MO) superlattices grown by dc sputtering at high oxygen pressures (3.5 mbar) show the expected ferromagnetic behaviour. However, field cooled hysteresis loops at…
Magnetic measurements on heavily overdoped $La_{2-x}Sr_xCuO_4$, $Tl_2Ba_2CuO_6$, $Bi_2Sr_2CuO_6$ and $Bi_2Sr_2CaCu_2O_8$ single crystals reveal a new type magnetization hysteresis loops characterized by the vanishing of usual central peak…
It is shown that in crystal lattices with a basis the cooperative behavior of a certain type of atoms performing optical long-wavelength vibrations in a double-well potential of the field of the matrix lattice may lead to the formation of a…
After the application of an ultrashort laser pulse, the antiferromagnetic alignment in rare earth-transition metal alloys can temporarily become ferromagnetic with the rare-earth polarity. Proposed models merely describe this effect,…
We report experimental results indicating possible high-temperature superconductivity in graphite intercalation compounds synthesized with lithium-based alloys. Temperature-dependent measurements of magnetization, trapped magnetic flux, and…
Clarifying the electronic and magnetic properties of lutetium, lutetium dihydride, and lutetium oxide is very helpful to understand the emergent phenomena in lutetium-based compounds (such as room-temperature superconductivity). However,…
Magnetotransport measurements performed on several well-characterized highly oriented pyrolitic graphite and single crystalline Kish graphite samples reveal a reentrant metallic behavior in the basal-plane resistance at high magnetic…
We present a x-ray dichroism study of graphite surfaces that addresses the origin and magnitude of ferromagnetism in metal-free carbon. We find that, in addition to carbon $\pi$ states, also hydrogen-mediated electronic states exhibit a net…
Considerable efforts have been devoted recently to synthesize diluted magnetic semiconductors having ferromagnetic properties at room temperature because of their technological impacts for spintronic devices. In 2001 successful growth of…
The temperature and field dependences of the trapped magnetic fields and of the frozen magnetoresistance of (Pb)Bi-Sr-Ca-Cu-O ceramics and Bi-based magnetron films are investigated. It is found that in the resistive transition region of…
Superconductivity has again become a challenge following the discovery of unconventional superconductivity. Resistance-free currents have been observed in heavy-fermion materials, organic conductors and copper oxides. The discovery of…
We consider a low-temperature plasma within a newly developed MHD Fluid model. In addition to the standard terms, the electron spin, quantum particle dispersion and degeneracy effects are included. It turns out that the electron spin…
The description and detection of unconventional magnetic states such as spin liquids is a recurring topic in condensed matter physics. While much of the efforts have traditionally been directed at geometrically frustrated antiferromagnets,…
We investigate the thermodynamic properties of Heisenberg ferrimagnetic mixed-spin chains both numerically and analytically with particular emphasis on the combination of ferromagnetic and antiferromagnetic features. Employing a new…
We report on isothermal magnetization, M\"ossbauer spectroscopy, and magnetostriction as well as temperature-dependent alternating-current (ac) susceptibility, specific heat, and thermal expansion of single crystalline and polycrstalline…