Nonstoichiometry and Thermodynamic Properties of Intermetallic compounds

本研究的目的是用电动势方法测量具有宽非化学计量比组成范围的B2型和AlB2型金属间化合物的活性。用固体电解质(ZrO_2(+MO)和CaF_2)构建电池，测量电动势，研究了大量的附加元素(Sb、Ge、Fe)对CoGa-B_2相镓的活度的影响，B_2结构的煤-NiAl化合物固溶体中Al的活度，NdGa_2和AlB_2 Nape结构的金属间化合物NdGa_2和LaGa_2中的Nd和La的活度。在COGA相的二元系中，我们确认了原始的活度数据。在1173和1273K，Sb的加入增加了Ga在整个成分范围内的活度。添加1mol%的Sb对活性影响不大，但添加2%和3%的Sb能有效地提高催化剂的活性，且增加的程度相似。添加Ge(2-6摩尔%)Inr…在整个构图范围内更轻松地与其量相对应的活动。但2%的SU对富Ga组分不起作用。随着Ni含量的增加，Ni(2~6摩尔%)的加入增加了富Co区的活性，而降低了富Ga区的活性。1Mole%Fe增加了富Co区的活性，但降低了富Ga区的活性。3摩尔%Fe提高了整个组成范围内的活性。Al在NiAl化合物固溶体中1000K的活度分别为：(NiAl：5.68×10；-4；-4；)，(Ni_&lt；42&gt；Co_8Al_&lt；50&gt；：6.78×10；-5)，(Ni_&lt；33&gt；C_&lt；17&gt；Al_&lt；50&gt；：3.9610^&lt；-5&gt；)，(Ni_&lt；17&gt；Co_&lt；；33；50；50；；1.68×10；-5；)，(煤炭：1.25×10；-5)。研究发现，Al的活性随着煤粉浓度的增加而降低。用含Mn、MnF_2参比电极的CaF_2电势法测定了NdGa_2(AlB_2型结构)中Nd的活度为：(X_&lt；ND&gt；=0.206-0.309α_&lt；-14&gt；~10^&lt；-11&gt；700K和α_&lt；ND&gt；=10^&lt；-11&gt；~10^&lt；-8&gt；在900K)，但由于电池的电动势不稳定，不能准确测定LaGa2中La的活性。较少

The aim of this study is to measure the activity in the intermetallic compounds with B2 and AlB_2 type structures which have wide composition range of non-stoichiometry by EMF methods. The cells are constructed with solid electrolytes (ZrO_2(+MO), and CaF_2) to measure the EMF and 1: the effect of amall amount of additional elements (Sb,Ge,Fe) on the activity of gallium in the CoGa-B2 phase, 2: activity of Al in CoAl-NiAl compound solid solution with B2 type structure, 3: activity of Nd and La in the intermetallic compounds of NdGa_2 and LaGa_2 with AlB_2 nape structure are studied.The following results are obtained.1. In the binary system of CoGa phase, original data of activity by us are confirmed. Addition of Sb increases the activity of Ga in the whole composition range at 1173 and 1273K. The effect of 1mol% Sb addition is small, but 2 and 3 mol% addition increase the activity effectively and the difference of the degree of increments is similar. Addition of Ge ( 2 to 6 mole%) incr … More eases the activity corresponding to its amount in the whole composition range. But 2%SU is not effective in the Ga rich composition. Addition of Ni (2 to 6 mole%) increases the activity in Co-rich region but decreases in the Ga-rich region with increasing Ni content. 1mole% Fe increases the activity in Co-rich region but decreases in the Ga-rich region. 3mole% Fe increases the activity in the whole composition range.2. Activity of Al at 1000 K in the compound solid solution of CoAl-NiAl is : (NiAl : 5.68×10^<-4>),(Ni_<42>Co_8Al_<50> : 6.78× 10^<-5>), (Ni_<33>C_<17>Al_<50> : 3.9610^<-5>), (Ni_<17>Co_<33>Al_<50> : 1.68×10^<-5>), (CoAl_<50> : 1.25×10^<-5>). It is found that the activity of Al decreases with the increasing of the CoAl concentration.3. By use of CaF_2 EMF method with Mn,MnF_2 reference electrode, activity of Nd in NdGa_2 (AlB_2 type structure) is determined to be : (x_<Nd>=0.206-0.309 α_<Nd>= 10^<-14> 〜10^<-11> at 700K and α_<Nd>= 10^<-11>〜10^<-8> at 900 K), but activity of La in LaGa2 could not be determined precisely because the EMF of the cell was not stable. Less