In this work, a facile and versatile solution route was used to fabricate room-temperature ferromagnetic fish bone-like, pteridophyte-like, poplar flower-like, cotton-like Cu@Cu2O architectures and golfball-like Cu@ZnO architecture. The ferromagnetic origins in these architectures were found to be around metal-semiconductor interfaces and defects, and the root cause for their ferromagnetism lay...

Cuprate La-R 4Ba2Cu2O10 shows ferromagnetic to antiferromagnetic phase transition by replacing La ions with rare earth R=Nd, Sm, Eu, and Gd ions at low temperature. We propose that the transition is caused by a competition between antiferromagnetic superexchange interaction of Cu spins via La ions and ferromagnetic superexchange interaction due to Hund’s rule coupling of spins of holes on oxyge...

This paper describes the recognition of micro non-magnetic (conductive) and ferromagnetic material with spinvalve magneto-resistance (SV-GMR) sensor. High frequency and static magnetic fields were applied to material for the recognition of the micro conductive and ferromagnetic material respectively. The SV-GMR sensor is used to detect the magnetic field variation occurred wherever the material...

We used ferromagnetic artificial pinning centers in superconducting NbTi wires to achieve a large critical current density (Jc) in a magnetic field. Four wires were fabricated that contained nanometer-sized arrays of Ni or Fe pins inside micron-sized filaments of Nb0.36Ti0.64 alloy. A ferromagnetic pin volume of only 2% Ni produced Jc’s ~e.g., 2500 A/mm 2 at 5 T, 4.2 K! that were comparable to ...

We present a scattering treatment of transport in S-F-S junctions with a small ferromagnetic metal region inside the junction. The charge carriers are assumed not to thermalize with the fer-romagnet conduction band, and the ferromagnetic and superconductor orders coexist close to the interfaces. This requires a small ferromagnetic region in the junction. Ferromagnetism in the junction provides ...

In sharp contrast to previous studies on FeRh bulk, thin films, and nanoparticles, we report the persistence of ferromagnetic order down to 3 K for size-selected 3.3 nm diameter nanocrystals embedded into an amorphous carbon matrix. The annealed nanoparticles have a B2 structure with alternating atomic Fe and Rh layers. X-ray magnetic dichroism and superconducting quantum interference device me...

We determine thermal entanglement in mean field clusters of N spin one-half particles interacting via the anisotropic Heisenberg interaction, with and without external magnetic field. For the xxx cluster in the absence of magnetic field we prove that only the N = 2 ferromagnetic cluster shows entanglement. An external magnetic field B can only entangle xxx anti-ferromagnetic clusters in certain...

We present a simple method for efficient DNA ligation utilizing the heat generation of ferromagnetic particles subjected to an ac magnetic field. We carry out the ligation of DNA fragments with cohesive ends using T4 DNA ligase immobilized on the surface of ferromagnetic particles. When a radio frequency alternating magnetic field is applied, ferromagnetic particles dissipate heat and DNA ligas...

A Hubbard model with a Nd-fold degenerate single-particle ground state has ferromagnetic ground states if the number of electrons is less or equal to Nd . It is shown rigorously that the local stability of ferromagnetism in such a model implies global stability: The model has only ferromagnetic ground states, if there are no single spin-flip ground states. If the number of electrons is equal to...

Single crystalline Bi1−xCaxMnO3 (0.74 ≤ x ≤ 0.82) were studied with neutron scattering, electron diffraction and bulk magnetic measurement. We discovered dynamic ferromagnetic spin correlations at high temperatures, which are replaced by antiferromagnetic spin fluctuations at a concomitant charge ordering and structural transition. Our results indicate that thermal-activated hopping of the Jahn...