title: Unusual spectral renormalization in hexaborides.
abstract: Employing high resolution photoemission spectroscopy, we studied the evolution of the spectral features in rare earth hexaboride single crystals as a function of temperature and 4f binding energy, where the variation of the 4f binding energy is obtained by changing the rare earth element. High energy resolution helped to reveal the distinct features corresponding to the various photoemission final states. Experimental results of CeB(6), a dense Kondo system, exhibit the growth of the features near the Fermi level with the decrease in temperature relative to the uncompensated local moment contributions. The valence band spectra of the antiferromagnetic compounds, PrB(6) and NdB(6), exhibit multiple features-the 4f ionization peaks (poorly screened features) appear at higher binding energies and the features in the vicinity of the Fermi level possessing significant 4f character are due to the well-screened photoemission final states. These results indicate finite hybridization between the 4f and B 2s2p conduction electronic states. Interestingly, the well-screened features in PrB(6) and NdB(6) exhibit unusual enhancement in intensity at low temperature.
authors.affiliation: Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India.
authors.forename: Swapnil
authors.initials: S
authors.lastname: Patil
authors.forename: Ganesh
authors.initials: G
authors.lastname: Adhikary
authors.forename: G
authors.initials: G
authors.lastname: Balakrishnan
authors.forename: Kalobaran
authors.initials: K
authors.lastname: Maiti
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D002586:Cesium / Q000737:chemistry*; D004583:Electrons; D009354:Neodymium / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011221:Praseodymium / Q000737:chemistry*
chemical_list: D001896:Boron Compounds; D002586:Cesium; D009354:Neodymium; D011221:Praseodymium