The {Y, Pr}–Ag–Si systems: isothermal sections and crystal structures

Isothermal sections of the phase diagrams were cons tructed at 1073 and 773 K for the Pr–Ag–Si system a nd at 873 K for the Y–Ag–Si system based on X-ray powd er diffraction data. The crystal structures of two ternary compounds in the Pr–Ag–Si system were refin ed by the Rietveld method: PrAg2Si2, СeAl2Ga2-type structure, Pearson symbol tI10, space group I4/mmm, unit-cell parameters a = 0.42084(1), c = 1.06735(2) nm at 1073 K and CeNi 2+xSb2-x-type structure, oI10, Immm, a = 0.42088(2), b = 0.42287(2), c = 1.06695(3) nm at 773 K; PrAgSi, LiBaSi-type structure, hP3, P-6m2, a = 0.42302(1), c = 0.41911(1) nm at 1073 K and LaPtSi-type structure, tI12, I41md, a = 0.42087(2), c = 1.46432(8) nm at 773 K.