122nd General Meeting of the KCS

Type Poster Presentation
Area Inorganic Chemistry
Room No. Grand Ballroom
Time 10월 19일 (금요일) 11:00~12:30
Code INOR.P-44
Subject Experimental and Theoretical Investigations for the n-doping Effects in the Ca11-xRExSb10-y (RE = Gd-Tm; 0.32(3) ≤ x ≤ 0.43(2), 0.19(1) ≤ y ≤ 0.51(1)) Series
Authors JunSu Lee, Tae-Soo You*
Department of Chemistry, Chungbuk Natioanl University, Korea
Abstract We recently reported the n-type dopant included novel Zintl phase Ca11-xRExSb10-y (RE = La, Ce, Nd, Sm; 0.18(4) ≤ x ≤ 0.42(2), 0.14(1) ≤ y ≤ 0.41(1)) system adopting the Ho11Ge10-type structure for thermoelectric application. As an extension of the research, we present a successive work including other n-type dopants in the Ca11-xRExSb10-y (RE = Gd-Tm; 0.32(3) ≤ x ≤ 0.43(2), 0.19(1) ≤ y ≤ 0.51(1)) system. Total six ternary Zintl compounds were successfully synthesized by arc-melting, and their crystal structures were characterized by both PXRD and SXRD analyses. In particular, two SXRD data of Ca10.60(4)Ho0.40Sb9.69(1) and Ca10.57(2)Tm0.43Sb9.63(1) were collected using synchrotron X-ray diffraction to obtain the further accurate structural information. All six compounds showed an isotypic crystal structures, which adopted the tetragonal Ho11Ge10-type structure (space group I4/mmm, Z = 4, Pearson code tI84) and contained nine crystallographically independent asymmetric atomic sites in a unit cell. To understand the overall electronic structure as well as chemical bonding, tight-binding linear muffin-tin orbital (TB-LMTO) calculations were performed using a hypothetical structural model of Ca10.5RE0.5Sb10 (RE = Dy, Ho), and density of states (DOS) and crystal orbital Hamilton population (COHP) curves were thoroughly interrogated. The temperature-dependent dc magnetization was also measured between 15 and 300 K under ZFC and FC conditions with a dc magnetic field of 10 kOe for three compounds including Ca10.35(9)Dy0.58Sb9.53(3), Ca10.60(4)Ho0.40Sb9.69(1) and Ca10.68(3) Er0.32Sb9.50(1).
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