Tadic B, Nowak U
Jozef Stefan Institute, P.O. Box 3000, 1001 Ljubljana, Slovenia.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61(4 Pt B):4610-3. doi: 10.1103/physreve.61.4610.
We show that Barkhausen noise in two-dimensional disordered ferromagnets with extended domain walls is characterized by the avalanche size exponent tau(s)=1.54 at low disorder. With increasing disorder the characteristic domain size is reduced relative to the system size due to nucleation of new domains and a dynamic phase transition occurs to the scaling behavior with tau(s)=1.30. The exponents decrease at finite driving rate. The results agree with recently observed behavior in amorphous Metglas and Fe-Co-B ribbons when the applied anisotropic stress is varied.
我们表明，具有扩展畴壁的二维无序铁磁体中的巴克豪森噪声在低无序度下的雪崩尺寸指数τ(s)=1.54。随着无序度增加，由于新畴的形核，特征畴尺寸相对于系统尺寸减小，并且发生动态相变至τ(s)=1.30的标度行为。指数在有限驱动速率下减小。这些结果与最近在改变施加的各向异性应力时非晶态金属玻璃和铁钴硼带中观察到的行为一致。
