INFLUENCE OF IN-PLANE FIELD ON THE CRITICAL TEMPERATURE FOR THE BREAKDOWN OF VERTICAL BLOCH LINE CHAINS

The influence of in-plane field H_ip on the critical temperature T₀ for the breakdown of vertical Bloch line (VBL) chains of hard domains in garnet bubble films has been inves-tigated experimentally. It was found that T₀ can be significantly reduced by the increase of H_ip. Besides, the critical in-plane field H′_ip for the breakdown of VBL chains was measured as a function of temperature T for the same sample. As a result, the correlation between these two critical parameters, T₀ and H′_ip, was found. By introducing an effective in-plane field (H_ip)_e, the positive definiteness of the system of VBL pairs with two-dimemsional magnetization distribution was analyzed, giving rise to a theoretical expression of H′_ip(T): H′_ip(T) =|4\piM_sQ(a₀+a₁Q +a₂Q²+a₃Q³+ a₄Q⁴)|^T_(T0(Hip=0)), where a_i are constants. It agrees well with the experiments.