X.F. Nie

Influence of preparing condition on magnetic properties of the FeCoNi–SiO2 granular alloy solids

Abstract FeCoNi–SiO 2 granular alloy solids have been prepared using a sol–gel method, and investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The influences of the preparing condition and the alloy concentration on the magnetic properties have been thoroughly studied. The dependences of the magnetic properties and the lattice constant of FeCoNi alloy particles on the Ni content have been discussed.

The annihilation of vertical-Bloch lines in the walls of hard domains to which bias fields and in-plane fields are alternately applied ☆

Abstract The annihilation of vertical-Bloch lines in magnetic domain walls of the ordinary hard bubbles, to which both bias fields and in-plane fields are alternately applied, is investigated experimentally. The influence of an in-plane magnetic field on ordinary hard bubbles (OHB), dumbbell domains of the first kind (ID), and dumbbell domains of the second kind (IID) was analyzed, and a critical in-plane field range [ H ip 0 , H ip 2 ] for vertical Bloch line (VBL) annihilation was found. For the three types of hard domains ( H ip 0 is the minimum critical in-plane field of VBLs which begin to be unstable, H ip 2 is the minimum critical in-plane field which only needs to be applied one time for collapse of all OHBs), the critical field range is the same with H ip 0 ≐8 πM s . We hypothesize that there exists a direction along which the vertical-Bloch lines in the domain walls are annihilated most easily. It is also observed that the stability of vertical-Bloch lines in the domain walls does not depend on the initial state. This provides a more detailed description of the minimum critical in-plane field than previously known.

Preisach studies on ZFC/FC magnetization behavior of sintered SrRuO3

Zero-field-cooled (ZFC) magnetization, field-cooled (FC) magnetization, AC magnetic susceptibility and major hysteresis loops of sintered SrRuO 3 have been measured over the range of magnetic ordering temperature. The data were analyzed within the framework of the Preisach model. The numerical simulations match the major features of ZFC/FC magnetization. The results indicate that various ZFC/FC behaviors originate from the applied field and the Barkhausen spectrum of the sample.

Formation of three kinds of hard domains by low-bias-field method

The formation of three kinds of hard domains (HDs) at low bias field was studied experimentally. Low-bias-field method provides a simple way to produce the three kinds of HDs in different proportions. Also, the relationship between the shape of the multi-branched domains (MBDs) and the different kinds of domains was studied. Most branches of the MBDs correspond to the first kind of dumbbell domains or the second kind of dumbbell domains; in contrast, few branches of the MBDs correspond to the hard bubbles or soft bubbles.

Influence of in-plane fields on the soft segments in garnet bubble films☆

Abstract The influence of in-plane field H ip on the soft segments in garnet bubble films was experimentally studied. It was found that H ip affects the stripe-to-bubble transition field of soft domain segments H sb and the collapse field of soft bubbles H 0 . Moreover, H sb and H 0 change along with H ip , and both of them are related to the crystal direction. Comparing the results for different crystal directions, we find a dividing in-plane field (H ip ) d related to the parameters of the samples. (H ip ) d is about two times of the saturation magnetization 4 π M s . The dividing in-plane field (H ip ) d thus divides the influence of H ip on soft segments into two regions: high H ip region and low H ip region.