相关论文: Room-temperature ferromagnetism in nanoparticles o…

Light-matter strong coupling in the vacuum limit has been shown to enhance material properties over the past decade. Oxide nanoparticles are known to exhibit weak ferromagnetism due to vacancies in the lattice. Here we report the 700-fold…

Room-temperature ferromagnetism has been observed in the nanoparticles (7 - 30 nm dia) of nonmagnetic oxides such as CeO2, Al2O3, ZnO, In2O3 and SnO2. The saturated magnetic moments in CeO_2 and Al_2O_3 nanoparticles are comparable to those…

ZnO nanoparticles with Wurtzite structure were prepared by chemical methods at low temperature in aqueous solution. Nanoparticles are in the range from about 10 to 30 nm. Ferromagnetic properties were observed from 2 K to room temperature…

A reentrant superconducting effect was observed in YBCO particles as a consequence of their size and microstructure. It rises from the coexistence between bulk superconductivity and surface ferromagnetism, where the enhanced…

We report observation of surface-defect-induced room temperature multiferroicity - surface ferromagnetism ($M_S$ at 50 kOe $\sim$0.005 emu/g), ferroelectricity ($P_R$ $\sim$2 nC/cm$^2$), and significantly large magnetoelectric coupling…

The magnetization as a function of magnetic field showed hysteretic behavior at room temperature. According to the temperature dependence of the magnetization, the Curie temperature $(T_{C})$ is higher than 350 K. Ferromagnetic Mn-doped tin…

The influence of YBa2Cu3O4 (YBCO) superconductor layer (S-layer) with varying thickness d-YBCO = 20 to 50 nm on the magnetic coupling between two La0.67Ca0.33MnO3 (LCMO) ferromagnet layers (F-layer, thickness d-LCMO = 50 nm) in F/S/F…

The in-plane thermal conductivity K(T) of Zn-doped YBCO single crystals (YBCO:Zn) has been investigated in the temperature range from 5 to 250 K and in magnetic fields up to 30 kOe. The thermal conductivity decreases substantially with…

Improved trapped fields are reported for bulk melt-textured YBa2Cu3O7-x (YBCO) material in the temperature range between 20 K and 50 K. Trapped fields up to 12.2 T were obtained at 22 K on the surface of single YBCO disks (with Ag and Zn…

LaCoO3 (LCO) nanoparticles were synthesized and their magnetic and structural properties were examined using SQUID magnetometery and neutron diffraction. The nanoparticles exhibit ferromagnetic long-range order beginning at T_C…

Occurrence of room temperature ferromagnetism is demonstrated in pulsed laser deposited thin films of Sn1-xCoxO2-d (x<0.3). Interestingly, films of Sn0.95Co0.05O2-d grown on R-plane sapphire not only exhibit ferromagnetism with a Curie…

The existence of coherent magnetic correlations in the normal phase of cuprate high-temperature superconductors has proven difficult to measure directly. Here we report on a study of ferromagnetic-superconductor bilayers of…

Magneto-optic studies of ZnO doped with transition metals Co, Mn, V and Ti indicate a significant magnetic circular dichroism (MCD) at the ZnO band edge at room temperature, together with an associated dispersive Faraday rotation. Similar…

Successful synthesis of room-temperature ferromagnetic semiconductors, Zn$_{1-x}$Fe$_{x}$O, is reported. The essential ingredient in achieving room-temperature ferromagnetism in bulk Zn$_{1-x}$Fe$_{x}$O was found to be additional Cu doping.…

The Laves phase compound, YCo2, is a well-known exchange-enahnced Pauli paramagnet. We report here that, in the nanocrystalline form, this compound interestingly is an itinerant ferromagnet at room temperature with a low coercive-field. The…

Scanning transmission x-ray microscopy has been used to image electric currents in superconducting films at temperatures down to 20 K. The magnetic stray field of supercurrents in a thin YBaCuO film is mapped into a soft-magnetic coating of…

We describe a simple AC susceptometer built in-house that can be used to make high-resolution measurements of the magnetic susceptibility of high-temperature superconductors in an undergraduate physics lab. Our system, cooled using liquid…

We report magnetic measurements up to 1200 K on three different multi-walled carbon nanotube mat samples using Quantum Design vibrating sample magnetometers. Three different samples prepared from arc discharge or chemical vapor deposition…

The structural, electrical and magnetic properties of the superconducting ferromagnets, Gd1.4-xDyxCe0.6Sr2RuCu2O10 (x=0-0.6) are systematically investigated as a function of Dy doping and temperature. These compounds are characterised by…

Materials of the Y-Ba-Cu-O (melt-textured YBa2Cu3O7-d-based materials or MT-YBCO) and Mg-B-O (MgB2-based materials) systems with high superconducting performance, which can be attained due to the formation of regularly distributed…