title: Ba(1-x)Na(x)Ti2Sb2O (0.0 ≤ x ≤ 0.33): a layered titanium-based pnictide oxide superconductor.
abstract: A new layered Ti-based pnictide oxide superconductor, Ba(1-x)Na(x)Ti(2)Sb(2)O (0.0 ≤ x ≤ 0.33), is reported. X-ray studies revealed that it crystallizes in the tetragonal CeCr(2)Si(2)C structure. The undoped parent compound, BaTi(2)Sb(2)O [P4/mmm; a = 4.1196(1) Å; c = 8.0951(2) Å], exhibits a charge density wave (CDW)/spin density wave (SDW) transition at 54 K. Upon chemical doping with Na, the CDW/SDW transition is systematically suppressed, and superconductivity arises with the critical temperature (T(c)) increasing to 5.5 K. Bulk superconductivity was confirmed by resistivity, magnetic, and heat capacity measurements. Like the high-T(c) cuprates and the iron pnictides, the superconductivity in BaTi(2)Sb(2)O arises from an ordered state. Similarities and differences between BaTi(2)Sb(2)O and the cuprate and iron pnictide superconductors are discussed.
authors.affiliation: Department of Chemistry, University of Houston, Houston, Texas 77204, USA.
authors.forename: Phuong
authors.initials: P
authors.lastname: Doan
authors.forename: Melissa
authors.initials: M
authors.lastname: Gooch
authors.forename: Zhongjia
authors.initials: Z
authors.lastname: Tang
authors.forename: Bernd
authors.initials: B
authors.lastname: Lorenz
authors.forename: Angela
authors.initials: A
authors.lastname: Möller
authors.forename: Joshua
authors.initials: J
authors.lastname: Tapp
authors.forename: Paul C W
authors.initials: PC
authors.lastname: Chu
authors.forename: Arnold M
authors.initials: AM
authors.lastname: Guloy