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 T₀₂ was found. When T > T₀₂, hard bubbles are no longer formed. It was also found that there are two different stages for VBL formation between R.T. and T₀₂. Their demarcation temperature is T₀₁. 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 T₀ for the break down of VBL chains was found (for the same sample, T₀ > T₀₂ > T₀₁). When the testing temperature T < T₀, the VBL chains are not changed after temperature increasing and then decreasing. When T > T₀, 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.