Effects of post-sintering annealing treatment between 300 and 1000ºC for up to 8 hrs time periods followed by either furnace cooling (FC) or air-cooling (AC) on the hard magnetic properties of some Nd-Fe-B based sintered magnets was investigated. It was shown that the intrinsic coercivity (Hci), second quadrant demagnetization loop shape and thus the energy density (BH)max varied considerably a...

In situ transmission electron microscopy study of electric field-induced cracking has been conducted on ^001& oriented 0.65Pb~Mg1/3Nb2/3!O3 – 0.35PbTiO3 crystal. Fracture of the 90° domain boundary was directly observed in the tetragonal area under both static and alternating electric fields. The field strength required to induce domain boundary cracking was lower for alternating electric field...

Low-temperature refrigeration is of crucial importance in fundamental research of condensed matter physics, because the investigations of fascinating quantum phenomena, such as superconductivity, superfluidity, and quantum criticality, often require refrigeration down to very low temperatures. Currently, cryogenic refrigerators with (3)He gas are widely used for cooling below 1 K. However, usag...

Based on the propagation rules of electromagnetic waves in metal conductors, this paper analyzes the characteristics of electric field and magnetic field of internal conductors. Then the complex power of electromagnetic wave is calculated. The impedance calculation formula of metal conductor is derived. Moreover, in order to identify and detect defects of metal casing, an alternating current im...

A square matrix is said to be alternating-clean if it is the sum of an alternating matrix and an invertible matrix. In this paper, we determine all alternating-clean matrices over any division ring K. If K is not commutative, all matrices are alternating-clean, with the exception of the 1× 1 zero matrix. If K is commutative, all matrices are alternating-clean, with the exception of odd-size alt...

We have excited and detected coherent spin waves in exchange-biased IrMn/Co systems by ultrafast laser pump-probe magneto-optical Kerr effect (MOKE). Such ultrafast measurements provide opportunity to study the ultimate time scale for these processes as well as determination of fundamental parameters such as anisotropy and damping. This is in analogy with ferromagnetic resonance (FMR), but with...

Formation conditions of single magnetic bubblesthrough in-plane field demagnetization are investigated in an array of Co/Ni circular dots by magnetic force microscopy and compared to micromagnetic calculations. We demonstrate high success rates in nucleating stable bubbles. The efficiency of single bubble formation is found to depend not only on the dot size, material thickness and intrinsic ma...

A leaky dielectric Newtonian drop suspended in another leaky dielectric Newtonian liquid medium deforms as it settles under the influence of a uniform alternating electric field. As a result of this deformation, the terminal velocity is affected. In this study we present a detailed experimental investigation of the effect of horizontally directed uniform alternating electric field on the settli...