Temperature Dependence of Formation and Break Down of VBL Chains in Bubble Stripe Domain Walls

Abstract

The method of single-pulse bias field was employed to study the temperature dependence of VBL chain formation for soft domain segments, which might be a simulation of the temperature dependence of the "write in" operation of BLM. A critical temperature To2 was found. When T > Toz, hard bubbles are no longer formed. It was also found that there are two different stages for VBL formation between R.T. and To2. Their demarcation temperature is Tol. As a simulation of BLM minor loops, the hard stripe domains corresponding to ordinary hard bubbles were selected to study the temperature stability of VBL chains. A critical temperature To for the break down of VBL chains was found (for the same sample, To > Toz > To'). When the testing temperature T < To, the VBL chains are not changed after temperature increasing and then decreasing. When T > To, however, they disappear, so that all hard domains become soft. When the VBLs in walls are compressed, the harder the domain, the lower its softening temperature. During softening, the way of VBL disappearance is sudden break down of the whole chain.

Influence of rotating in-plane field on vertical Bloch lines in the walls of second kind of dumbbell domains

“…The experiments are performed as follows: (1) form a group of IIDs by applying a series of pulses on soft segments at the 'fixed static bias field' ðH b Þ 0 [4], count the number of IIDs (writen as N 0 ); (2) slowly decrease H b to zero and applying an inplane field of appropriate magnitude for 1 min, lower it to zero; (3) rotate the sample in the plane for an angle of Dj; applying an in-plane field of the same value in step (2) for 1 min, and then lower it to zero; (4) repeat step (3) …”

“…As for IIDs with even longer VBL chains, they will shrink in length with the increase of H b ; but will never contract to circular form, then they will eventually collapse in dumbbell form over a quite narrow range of H b between H 0 0 and H IID;max : In fact, the above remarkable differences are the basis of the classification scheme [1,2]. Furthermore, this scheme has made it possible to study the stability of VBL chains subjected to in-plane field for each type of hard domains formed by the series-pulse method [4]. In this article, we will investigate the annihilation of VBLs in the walls of IIDs.…”

Study on additive effective interaction between vertical Bloch lines

“…Their static parameters and characteristic bias fields at room temperature (RT) are listed in Table 1. Three kinds of hard domains can be reproduced in the above samples using the series pulse method given in Section 2.1 [8,10]. We have measured the dependence of the collapse field H col on the stripe-tobubble transition field H sb of OHB and ID, and also the dependence of the collapse bubble diameter d col on the collapse field H col .…”

“…In the last ten years, we have studied the stability of vertical Bloch lines (VBLs) by the new classification of three kinds of hard domains [8][9][10][11][12][13][14][15]. In this paper we list some experimental phenomena that could not be explained by the known theory, present an assumption about an additive effective interaction energy between vertical Bloch lines, and thereby give a uniform explanation of these phenomena.…”

Influence of Temperature on Equilibrium Separation Between Vertical Bloch Lines in OHBs in Garnet Bubble Films

“…[8−12] The critical temperature 𝑇 0 for the breakdown of the VBLs in garnet stripe domain walls was first found in 1988. [8] In 1992, Han et al [9] attempted to explore the mechanism of the critical temperature for the breakdown of VBLs. They calculated the temperature dependence of the equilibrium separation 𝑆 𝑒𝑞 by…”