Negative oxygen isotope effect on the static spin stripe order in superconducting La2-xBaxCuO4 (x=1/8) observed by muon-spin rotation

Abstract

Large negative oxygen-isotope (O16andO18) effects (OIEs) on the static spin-stripe-ordering temperature Tso and the magnetic volume fraction Vm were observed in La2-xBaxCuO4(x=1/8) by means of muon-spin-rotation experiments. The corresponding OIE exponents were found to be αTso=-0.57(6) and αVm=-0.71(9), which are sign reversed to αTc=0.46(6) measured for the superconducting transition temperature Tc. This indicates that the electron-lattice interaction is involved in the stripe formation and plays an important role in the competition between bulk superconductivity and static stripe order in the cuprates. © 2014 American Physical Society.