纯铁中运动畴壁引起的低频内耗

在匀速增加磁场的条件下测量了纯铁试样在退火和预应变时的低频内耗。结果表明,磁化过程中的动态内耗是一种与磁化场增加速率成正变关系,与测量频率成反变关系的粘弹性内耗。而稳态磁场下的内耗则与测量频率有正变关系。这与作者对镍的测量结果类似。结果还表明,预应变使这两种内耗减小,峰值移向高场。关键词：

LOW FREQUENCY INTERNAL FRICTION OF MOVING MAGNETIC DOMAIN WALLS IN PURE IRON

The low frequency internal friction (Q^-1) of pure iron wires in a d.c. magnetic field increasing with a constant rate (H = const) was studied by a torsion pendulum a room temperature. It was found that Q^-1 is composed of a static part Q₀^-1 (at H=0) and a dynamic part Q_m^-1 (at H≠0) which is viscoelastic type. The values of Q_m^-1 are independent of the strain amplitude A_ε (in the range of 10^-6 to 10^-5), increase with the increase of H/ω and drop almost down to the ualues of Q₀^-1 when H changes suddenly from some ualue to zero. The behaviour of the static part is analogous to that of the resonance damped model of dislocation. The Q_m^-1-H curves of prestrained specimens are lower than those of annealed Ones and their peaks shift to higher magnetic field.