The effect of Nb additions on the thermal stability of melt-spun Nd2Fe14B
The effect of Nb additions on the thermal stability of melt-spun Nd2Fe14B
复制标题
Nb添加量对熔纺Nd2Fe14B热稳定性的影响
DOI：
10.1063/1.369916
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发表时间：
1999
影响因子：
3.2
通讯作者：
V. Panchanathan
中科院分区：
文献类型：
--
作者：
L. H. Lewis;K. Gallagher;V. Panchanathan
高温超导量子干涉仪（SQUID）的磁力测量进行了两个样品的熔体旋转和最佳退火的Nd 2Fe 14 B;一个样品含有2.3重量%的Nb和一个是无Nb。 在T=630 K（高于2-14-1相的居里温度）下，用SQUID磁力计测量了连续的全磁滞回线，作为场（1 T H −1 T）和时间的函数，在10−6 Torr的真空下对密封在石英管中的粉末样品进行测量。 所测得的磁滞信号被解构成高场线性顺磁部分和低场铁磁信号的来源不明。虽然来自两个样品的铁磁信号的饱和磁化强度随时间增长，但来自含Nb样品的信号总是较小。的结晶度数据是一致的，在含Nb的样品中的恒定的杂质颗粒尺寸和增加的杂质颗粒尺寸在无Nb的样品。结果表明，Nd_2Fe_（14）B型相的顺磁磁化率信号与Nb-Fe_（14）B型相的顺磁磁化率信号基本一致。
Elevated-temperature superconducting quantum interference device (SQUID) magnetometry was performed on two samples of melt-spun and optimally annealed Nd2Fe14B; one sample contained 2.3 wt % Nb and one was Nb-free. Continuous full hysteresis loops were measured with a SQUID magnetometer at T=630 K, above the Curie temperature of the 2–14–1 phase, as a function of field (1 T⩽H⩽−1 T) and time on powdered samples sealed in quartz tubes at a vacuum of 10−6 Torr. The measured hysteresis signals were deconstructed into a high-field linear paramagnetic portion and a low-field ferromagnetic signal of unclear origin. While the saturation magnetization of the ferromagnetic signal from both samples grows with time, the signal from the Nb-containing sample is always smaller. The coercivity data are consistent with a constant impurity particle size in the Nb-containing sample and an increasing impurity particle size in the Nb-free sample. The paramagnetic susceptibility signal from the Nd2Fe14B-type phase in the Nb-fr...