Study on Nitrogenation and Hydrogenation of MgAgAs-type Compounds

我们开发了一种仪器，用于研究室温以上高温下的固气反应。通过测量气体压力的变化来检测固体对气体的吸收或解吸。这种方法被称为“热压分析”，简称TPA。它使我们能够非常灵敏地检测气体与固体的反应。当使用氢气时，它的强力点被标记出来。由于在反应中观察到的是气体压力的较大变化，而不是质量的微小变化，因此试图精确地检测气体压力的微小变化。对TPA装置的硬件和软件作了许多修改。进行了精密的TPA自动测量。利用个人计算机对TPA进行自动测量；记录来自温度计和压力传感器的电信号。氮气、氢气、氧气、氩气和氨气的最大气体压力可达0.2 MPa。在600℃以上，CoTiSn的氮吸收过程已被清楚地观察到，用中子衍射和EPMA对CoTiSn的氮化产物进行了广泛的研究。结果表明，化合物中的氮原子与钛原子发生选择性反应

We have developed an instrument for studying the solid-gas reaction at elevated temperatures above R.T. The change in gas pressure is measured to detect gas absorption or desorption by/from solid. This method is called "thermopiezic analysis", TPA. It allows us great sensitive detection of gas reaction with solid. When hydrogen gas is employed, its strong point is marked. Since larger changes in gas pressure are observed rather than small changes in mass in the reactionA precise detection of very small change in gas pressure was tried. Many modifications have been given to the hardware as well as software in the TPA apparatus. Sophisticated automatic measurement of TPA was performed. A personal computer is used to make an automatic measurement of TPA ; electric signals from a thermometer and a pressure transducer are recorded. The maximum gas pressure was raised up to 0.2 MPa for nitrogen, hydrogen, oxygen, argon and ammoniaThe CoTiSn compound was investigated mostly by the TPA. The nitrogen absorption process has been clearly observed in CoTiSn above 600 C. The nitrogenation products of CoTiSn was extensively investigated by means of the neutron diffraction and EPMA. It was indicated that the nitrogen atoms react selectively with Ti atoms in the compounds