Published September 21, 2005 | Version v1
Journal article

Oxygen isotope effect on metal-insulator transition in layered cobaltites RBaCo2O5.5 (R = Pr, Dy, Ho and Y)

  • 1. Laboratory for Developments and Methods, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)
  • 2. Laboratory for Neutron Scattering, ETH Zuerich and Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

Description

Both differential scanning calorimetry and powder neutron diffraction have been applied to investigate an oxygen isotope effect on the metal-insulator (MI) transition in layered cobaltites RBaCo2O5.5 (R = Pr, Dy, Ho and Y). For all the compounds it was found that 18O substitution increases the transition temperature TMI by about 2 K. A small negative isotope-effect coefficient α0∼-0.06 indicates that a delocalization of the pd σ holes in the Co3+ high spin state (rather than a spin-state transition) can be responsible for the MI transition, in agreement with density-functional calculations (Wu 2003 J. Phys.: Condens. Matter 15 503)

Availability note (English)

Available online at http://stacks.iop.org/0953-8984/17/5813/cm5_37_016.pdf or at the Web site for the Journal of Physics. Condensed Matter (ISSN 1361-648X) http://www.iop.org/

Additional details

Publishing Information

Journal Title
Journal of Physics. Condensed Matter
Journal Volume
17
Journal Issue
37
Journal Page Range
p. 5813-5820
ISSN
0953-8984
CODEN
JCOMEL