An NMR study of nitriding process of Sm2Fe17

被引：0

作者：

Kapusta, C ^{[1
]}

Riedi, PC ^{[1
]}

Tomka, GJ ^{[1
]}

Kocemba, W ^{[1
]}

Brennan, S ^{[1
]}

Coey, JMD ^{[1
]}

机构：

[1] Univ St Andrews, Dept Phys & Astron, JF Allen Labs, St Andrews KY16 9SS, Fife, Scotland

来源：

RARE-EARTH MAGNETS AND THEIR APPLICATIONS, VOLS 1 AND 2 - PROCEEDINGS OF THE 14TH INTERNATIONAL WORKSHOP | 1996年

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D O I：

暂无

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The results of a study of the NMR spectra of Sm-147 and Sm-149 in Sm2Fe17 powders nitrided under different conditions in NH3 and N-2 are reported. The power dependence of the signal and the echo decays of the spin echo spectra in zero applied field, were measured to obtain information on the distribution of the nitrogen interstitials adjacent to Sm sites. The spectra correspond to domain wall edge signals. Differences in quadrupole splittings and hyperfine fields arise from Sm 6c sites with different numbers of N neighbours (0 to 3) at the 9e interstitials. The NMR signal from each site is in the form of a septet (nuclear spins 7/2). The contribution to the overall spectrum from each septet depends on the nitriding conditions. Different conditions result in different nitrogen distributions and thus, in differences in the domain wall structure. From the variations in the intensity of the septets on annealing, the changes of nitrogen distribution and the domain wall structure are deduced. The 0 N septet appearing in some samples nitrided for a short time reveals the presence of unnitrided material. NMR can detect 1% of unnitrided material. The signal for fine milled nitride powders does not change upon saturation of samples in a 7 T field, showing that the domain walls at the interface with unnitrided regions are not removed even in such high fields.

引用

页码：B217 / B226

页数：4