Pressure-induced phase transitions in lanthanide monoantimonides with a NaCl-type structure - art. no. 132101

By use of synchrotron radiation the powder x-ray diffraction of LnSb (Ln=la nthanide) with a NaCl-type structure has systematically been studied up to 40 GPa at room temperature. First-order phase transitions with the crystall ographic change occur for LnSb at high pressures. The structure of the high -pressure phases of LnSb is classified into three groups. The lighter LnSb (Ln=La, Ce, Pr, and Nd) have the tetragonal structure (distorted CsCl-type) at high pressures. The high-pressure form of the middle LnSb (Ln=Sm, Gd, a nd Th) is unknown. The heavier LnSb (Ln Dy, Ho, Er, Tm, and Lu) show the ty pical NaCl-CsCl (B1-B2) transition at high pressures though the same transi tion is not observed in the heavier LnP and LnAs. The transition pressures of LnSb increase with decreasing lattice constant in the NaCl-type structur e and do not depend on the structure of their high-pressure phases. The hig h-pressure structural behavior of LnSb is discussed.