METHOD OF PRODUCING SERIES OF LAYERED HETEROMETALLIC SELENIUM POLYCRYSTALS BaRECuSe (RE= Pr, Nd, Tb, Gd, Dy, Ho, Y, Tm, Er, Yb, Lu) OF CMCM SYMMETRY Russian patent published in 2025 - IPC C30B28/00 C30B29/46 C01B19/00 C01F11/00 C01F17/30 C01G3/00 

FIELD: chemistry.

SUBSTANCE: invention relates to solid-state chemistry and can be used in the manufacture of promising nonlinear and infrared optics materials, having low lattice thermal conductivity, semiconductor and thermoelectric materials with high quality factor, photoanodes in multi-junction solar cells, as well as photoelectric cells of solar batteries and thermoelectric generators. Invention is intended to produce a series of layered heterometallic selenium polycrystals of Cmcm symmetry and composition BaRECuSe₃, where RE is one of the following elements: Pr, Nd, Gd, Tb, Dy, Ho, Y, Tm, Er, Yb, Lu. Synthesis of said compounds is carried out as follows. Roasting oxides Pr₆O₁₁/Tb₄O₇ at 470 K or RE₂O₃, where RE is one of the following elements: Nd, Gd, Dy, Ho, Y, Er, Tm, Yb, Lu, at 1120 K for 5 h. At temperature of 330 to 350 K, said oxides and mechanically treated copper are dissolved in 10% excess of HNO₃, taken in the following stoichiometric ratios: RE₂O₃:2Cu, Pr₆O₁₁:6Cu or Tb₄O₇:4Cu. Obtained solution is diluted with distilled water to 800 ml with dissolution of Ba(NO₃)₂ in the ratio RE₂O₃:2Cu:2Ba(NO₃)₂, Pr₆O₁₁:6Cu:6Ba(NO₃)₂ or Tb₄O₇:4Cu:4Ba(NO₃)_2. Solution of nitrate salts containing said cations is evaporated. Obtained nitrate hydrates are then co-crystallized and subjected to high-temperature decomposition at 1000 to 1080 K to obtain an oxide precursor which is a multicomponent oxide system containing Ba(Pr,Tb)O₃ or Ba(Nd,Gd,Dy,Ho,Er,Yb,Y,Lu,Tm)₂CuO₅ and from two to six oxide compounds containing at least two said s-, d- or ƒ-elements. Obtained oxide precursor is subjected to mechanical homogenisation and treated with a mixture of hydrogen selenide and hydrogen. To obtain BaPrCuSe₃ the treatment is carried out for 1 h at 850 K, 3 h at 900 K, 1 h at 930 K and 2 h at 950 K. To obtain BaRECuSe₃, where RE is one of the following elements: Tb, Dy, Ho, Er, Tm, the treatment is carried out for 1 h at 890 K, 2 h at 930 K, 1 h at 970 K, 1 h at 1000 K, 1 h at 1040 K and 1 h at 1080 K. To obtain BaRECuSe₃, where RE is one of the following elements: Nd, Yb, Lu, Y, the treatment is carried out for 1 h at 890 K, 1 h at 930 K, 2 h at 970 K, 2 h at 1000 K and 1 h at 1040 K. To obtain BaGdCuSe₃, the treatment is carried out for 1 h at 890 K, 1 h at 930 K, 1 h at 970 K, 1 h at 1000 K, 1 h at 1040 K, 1 h at 1080 K and 1 h at 1120 K.

EFFECT: invention increases output of the main phase – said layered heterometallic selenium polycrystals, as well as reduces temperature and duration of the process.

11 cl, 7 dwg, 1 tbl, 11 ex