2008/08/01 by Udai Raj Singh, Singh, Udai Raj, S. Chaudhuri +5
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.0808.0067
4 pages, 8 figures
openalex publication_date 2008/08/01 · arxiv created 2008/10/07 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The electronic density of states (DOS) of La0.625Ca0.375MnO3(LCMO) strain free epitaxial thin films with an insulator-metal transition temperature (TIM) of 250 K was probed using variable temperature scanning tunneling microscopy and spectroscopy. We find a depression in the DOS with a finite zero bias conductance (ZBC) signifying a pseudogap (PG) in 78-310 K temperature range. With cooling, the ZBC is found to increase indicating an increased DOS near EF. We interpret PG as a signature of Jahn-Teller polarons while ZBC change, in agreement with the bulk insulator-metal transition, optical Drude peak, and photoemission experiments indicates the presence of free carriers at the Fermi energy in the metallic phase. The free carriers are discussed in terms of correlated polaronic states.