Control of functions of hydrogen absorbing alloys using strong magnetic fields

(1)实验研究了LaCo_5-H体系在零场和磁场中的反应热。在12 T磁场作用下，反应热提高了5%。这一数值与基于化学反应中磁热力学效应一般公式的计算结果吻合得很好。这是第一次观察到磁场对反应热的影响。(2)测量了LaCo_5的氘代和氘代磁性。β相LaCo_5H（D）_<3.4>与金属相LaCo_5一样，被认为是饱和铁磁体。γ相LaCo_5H（D）_&lt;3，4&gt;在35 T（氢化物）或38 T（氘化物）的临界磁场下发生变磁转变。这些磁性与电子结构有关。提出了一种利用LaCo_5在303 K、5 T磁场作用下的磁场效应分离氢同位素的新方法，该方法利用LaCo_5的磁场效应使气相中的氘得到富集。(3)测量了PrCo_5和CeCo_5的氘代物和氘代物的压力-组成等温线。在PrCo_5H（D）_x的β_1+γ区发现了同位素效应。CeCo_5H_x在237 - 313 K温度范围内出现3个平台区，最高可达5 MPa，磁场引起的平衡压力变化CeCo_5D_x比CeCo_5H_x大。(4)在<0.6>Spring-8用高能X射线（115 keV）观测了PdH_2单晶的康普顿分布。

(1) The heat of reaction was investigated experimentally for the LaCo_5-H system in zero field and a magnetic field. Under the influence of magnetic field of 12T the heat of reaction was increased by 5%. This value agreed well with the calculation based on the general formulation of magnetothermodynamic effects in chemical reactions. This is the first observation of the magnetic field effect on the heat of reaction.(2) The magnetic properties of LaCo_5 hydrides and deuterides were measured. The βphase LaCo_5 H (D)_<3.4> is recognized as a saturated ferromagnet, like the metal phase LaCo_5. The γ phase LaCo_5H (D)_<3,4> undergoes a metamagnetic transition at a critical field of 35T (hydride) or 38T (deuteride). These magnetic properties are related to the electronic structure. A new method for hydrogen isotope separation was proposed on the basis of a magnetic field effect using LaCo_5 under the magnetic field of 5T at 303K.The deuterium in the gaseous phase was enriched due to the applied magnetic fields.(3) The pressure-composition isotherms for the hydrides and the deuterides of PrCo_5 and CeCo_5 were measured. The isotope effect was discovered for the β_1+γ region of the PrCo_5H (D)_x. The CeCo_5H_x showed three plateau regions up to 5MPa in the temperature range between 237K and 313K.The magnetic field induced change in the equilibrium pressure for the CeCo_5D_x was higher than CeCo_5H_x.(4) Compton profiles were observed for PdH_<0.6> single crystals using high energy x-ray (115keV) at Spring-8.