%0 Journal Article
%J Physica B-Condensed Matter
%D 2009
%T Hydrostatic pressure study of the structural phase transitions and superconductivity in single crystals of (Ba1-xKx)Fe2As2 (x=0 and 0.45) and CaFe2As2
%A Torikachvili, M. S.
%A Bud'ko, S. L.
%A Ni, N.
%A Canfield, P. C.
%K 43 k
%K arsenides
%K h-c2
%K pressure effects
%K superconductivity
%M ISI:000271357300089
%P 3223-3226
%R 10.1016/J.Physb.2009.07.117
%U ://000271357300089
%V 404
%X We studied the effect of hydrostatic pressure (P) on the structural phase transitions and superconductivity in the ternary and pseudo-ternary iron arsenides CaFe2As2, BaFe2As2, and (Ba0.55K0.45)Fe2As2, by means of measurements of electrical resistivity (rho) in the 1.8-300 K temperature (T) range, pressures up to 20 kbar, and magnetic fields up to 9 T. CaFe2As2 and BaFe2As2 (lightly doped with Sn) display structural phase transitions near 170 and 85 K, respectively, and do not exhibit superconductivity in ambient pressure, while K-doped (Ba0.55K0.45)Fe2As2 is superconducting for T<30 K. The effect of pressure on BaFe2As2 is to shift the onset of the crystallographic transformation down in temperature at the rate of similar to-1.04 K/kbar, while shifting the whole rho(T) curves downward, whereas its effect on superconducting (Ba0.55K0.45)Fe2As2 is to shift the onset of superconductivity to lower temperatures at the rate of similar to-0.21 K/kbar. The effect of pressure on CaFe2As2 is first to suppress the crystallographic transformation and induce superconductivity with onset near 12 K very rapidly, i.e., for P<5kbar. However, higher pressures bring about another phase transformation characterized by reduced-resistivity, and the suppression of superconductivity, confining superconductivity to a narrow pressure dome centered near 5 kbar. Upper critical field (H-c2) data in (Ba0.55K0.45)Fe2As2 and CaFe2As2 are discussed. (C) 2009 Elsevier B.V. All rights reserved.
%Z 513XLTimes Cited:0Cited References Count:19
%8 10/15
%@ 0921-4526