The First Kind Of Dumbbell Domains In Garnet Bubble Film Temperature Characteristics

The ultra high density Bloch Line Memory (BLM) scheme was proposed byKonish in 1983. Negative vertical Bloch line (VBL) pairs in the walls of stripe domains aligned in parallel (minor loops) are used as information carries in BLM. So, the study of the temperature stability of the VBL in the magnetic domain of garnet bubble is very important to the study of BLM and the development of magnetic domain wall physics.By now, a lot of significant works have been done. The domain which include a large number of VBLs in domain walls are called hard domains. The hard domains are classified in three kinds by Nie Xiangfu et al i. e. ordinary hard bubble (OHB), the first kind of dumbbell domain (ID), and the second kind of dumbbell domain (IID).In 1992, Li Zhiqing's master degree paper, the temperature stability of vertical Bloch line (VBL) chains in walls of second hard dumbbell domain (IID) in the uncompressed state was investigated experimentally and athreshold temperature (7)nD at which to breakdown the VBL chains in thewalls of IID was found. Li united ordinary hard bubble (OHB), the first kind of dumbbell domain (ID) and the second kind of dumbbell domain for the first time and investigated the behavior of these three kinds harddomains. It indicated that the threshold temperature 7J,1 of three kindof domains are identical. That is to say, when temperature reach 7J,1, VBLin the walls of the three kinds hard domain begin to lose gradually. My tutor -Mr. Sun has studied hard domains experimentally, and he indicted that the structure of the wall of all hard domains are identical.In 1992, Han Baoshan et al analyzed the mechanism of the criticaltemperature for the breakdown of VBL chains. He claimed that the equil ibrium separation (S ) between neighbor ing VBL 1 ines decrease wi ththe raising of temperature.Based on their experiment, in this paper, the temperature stability of VBL in walls of the first kind hard dumbbell domain in the compressed state was investigated experimentally. In the first experiment, the identity of all hard domains was investigated. Secondly the length change of ID with temperature was investigated in detail. We found that the length of ID s increase with the raising of temperature. By analyzing the result, we demonstrate the equilibrium separation (S) between neighboring VBLlines increase with the raising of temperature. In the third experiment of the paper, the variation of T0 with the change of bias field was studied.The result is that 7J,1 doesn't change under the effect of low bias field.When exerted by high bias field, TQ decrease with the increasing of biasfield. From these results, it is testified that VBL distribute partly in the walls of ID. In the last part of this paper, the critical temperature with the bias field was investigated. It was found that the critical temperature T0doesn't change under the effect of low bias field too, when exerted by high bias field, T0 decrease with the increasing of bias field. By analyzing the results gotten from this experiment, from another aspect, the VBL distribute partly in the walls of ID was demonstrated.