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本工作依据微分磁化率的观测,以研究铁、镍、和几种铁钴合金在室温和高温下的“趋近饱和”现象。由实验结果得知,在数百到6000奥斯特的磁场下 微分磁化率和磁场强度的关系可用下式表出: (I/H)_T=A/H~2+2B/H~3+C/H~(1/2)+D,式中I表磁化强度,H表磁场强度,T表温度。在室温附近,式中末两项比前两项小得多,所以末两项的总值可以约略用一常数来代替;但在高温下就不然了。如果将一曾经驯炼的试品逐步加以冷作 则系数A和B最初跟冷作程度作跳跃式的增加;但对于经过剧烈冷作的试品上式就不适用。在驯炼状态下,A和B跟温度的上升而减小;到消失时温度还相当低于居里点。因本实验中所得数据的准确度不够所以不能依据它们来确定D的值;但如果将D略去而计算系数C的值,则可以确定到九成。C的数量级和它跟温度变化的情形大致是和Holstein和Primakoff的理论相符的 系数B和“磁晶各向异性”系数K的平方成正比;但用B的实验值和B的理论式比较而算得的K_1则和从单晶体观测所得的K_1只有数量级的符合。
This work is based on the observation of differential magnetic susceptibility to study the phenomenon of “approaching saturation” of iron, nickel, and several iron-cobalt alloys at room temperature and high temperature. The experimental results show that the relation between the differential magnetic susceptibility and the magnetic field strength in the magnetic field of several hundreds to 6000 oersteds can be expressed as follows: (I / H) _T = A / H ~ 2 + 2B / H ~ 3 + C / H ~ (1/2) + D, where I table magnetization, H table magnetic field strength, T table temperature. Near room temperature, the last two terms are much smaller than the first two, so the total value of the last two terms can be roughly replaced with a constant; but not at high temperatures. Coefficients A and B initially increased in a leaner fashion than in cold work if the tempered test sample was gradually cooled down; however, the above formula does not apply to severely cold samples. In tame state, A and B decrease with increasing temperature; to disappear, the temperature is still below Curie point. Since the data obtained in this experiment are not accurate enough, the value of D can not be determined from them; however, if D is omitted and the value of the coefficient C is calculated, then 90% can be confirmed. The magnitude of C and its relation to the temperature change are approximately proportional to the square of the coefficient of magnetic anisotropy K that is consistent with the Holstein and Primakoff theory; however, by comparing the experimental value of B with that of B Calculated K_1 is only orders of magnitude consistent with K_1 obtained from monocrystal observations.