33.6 Intermetal l ic Compounds (Intermetal l ic Phases) I Future 1. The structure of amb differs from those of either a or b 2. Its composition is variable to more or less extension 3. Mixed bonding 4. Intermediate properties
§3.6 Intermetallic Compounds (Intermetallic Phases) ◆ Ⅰ. Future 1. The structure of AmBn differs from those of either A or B 2. Its composition is variable to more or less extension 3. Mixed bonding 4. Intermediate properties
I Format ion A-B The property of Am Bn is between that of A and B
◆ Ⅱ. Formation A→←B The property of AmBn is between that of A and B
lll. Factor governing the structure of compounds 1)Electrochemical factor (X 2) Electron concentration(e/a) 3)Size factor Metal Nonmetal metalloid
◆ Ⅲ. Factor governing the structure of “compounds”. 1) Electrochemical factor (X) 2) Electron concentration (e/a) 3) Size factor Metal Nonmetal Metalloid
33.7 Normal Valence Compounds I Definition If the number of valence electrons of the cation is suficient to complete octahedron of the anion, the compound is called the normal valence compounds EXample: CmA mec=n(8 -) sometimes: m(ec-ecc-n(8-eaeAA)
§3.7 Normal Valence Compounds Ⅰ. Definition: If the number of valence electrons of the cation is sufficient to complete octahedron of the anion, the compound is called the normal valence compounds. Example: CmAn meC＝n(8－eA) sometimes: m(eC－eCC)＝n(8－eA－eAA)
Classification according to structure 1. NaCl and CaF2 types Nacl (Mg Ca Sr Ba)(se Te (Mn Pb Sn)(Se Te CaF? PtSn, PtIn, pt,P Anti-caF Mg,(si Ge Sn Pb) CuSe LiRAIN LiMgn as Sb Bi) AgMgAs
◆ Ⅱ. Classification according to structure 1. NaCl and CaF2 types NaCl: (Mg Ca Sr Ba)(Se Te) (Mn Pb Sn)(Se Te) CaF2: PtSn2 PtIn2 Pt2P Anti-CaF2: Mg2(Si Ge Sn Pb) Cu2Se Li3AlN2 LiMg(N As Sb Bi) AgMgAs