材料期刊网

测定了面心立方结构Fe-Mn-Al,Fe-Mn-Cr合金的电阻率及磁化率与温度的关系,这些合金均呈现顺磁性-反铁磁性转变,并伴有电阻率-温度关系的反常变化.电阻率测定的结果说明,在Néel温度T_N以下,由于反铁磁有序散射,使电阻率反常增大,dρ/dT减小或变为负值,ρ-T曲线向上弯曲,反常电阻率随T_N的下降和X-T曲线峰值的升高而增大.Al的加入量对反铁磁转变引起的电阻率变化有强烈的影响,随Al浓度的增加,反常电阻率急剧增大,这可能与Al使合金中Fe离子位置存在较大局域净磁矩有关.Cr对反铁磁电阻率的影响远较Al小.本文的实验结果揭示,基于顺磁性-反铁磁性转变,研制一种温度系数较小的Fe-Mn-Al-Cr系新电阻合金是可能的。

Measurement was carried out of the temperature dependence of the antiferromagnetic fcc Fe-Mn-Al and Fe-Mn-Cr alloys upon the electrical resistivity and magnetic susceptibility. A paramagnetic-antiferromagnetic transition together with an anomaly of resistivity of them is obtained. Owing to antiferromagnetism, ordered scattering,the anomaly of resistivity increases the dρ/dT decreases even becomes a negative divergence and the ρ-T plot turns upward at temperature below T_N. The anomalous resistivity increases with the decrease of T_N and the raise of the peak value on susceptibility. The amount of Al addition is vigorously influenced on the variation of magnetic resistivity induced by the antiferromagnetic transition. The more Al they contain, the more sharp increment it is. But the effect of Cr on the resistivity is far inferior to that of Al. As the resuit of the paramag netic-antiferromagnetic transition, it would be believed in the possibility of developing a new Fe-Mn-Al-Cr resistance alloy with low temperature coefficient.