Surface properties ofSmB6from x-ray photoelectron spectroscopy

Abstract

We have investigated the properties of cleaved SmB 6 single crystals by x-ray photoelectron spectroscopy. At low temperatures and freshly cleaved samples a surface core level shift is observed which vanishes when the temperature is increased. A Sm valence between 2.5 and 2.6 is derived from the relative intensities of the Sm 2+ and Sm 3+ multiplets. The B/Sm intensity ratio obtained from the core levels is always larger than the stoichiometric value. Possible reasons for this deviation are discussed. The B 1s signal shows an unexpected complexity: An anomalous low energy component appears with increasing temperature and is assigned to the formation of a suboxide at the surface. While several interesting intrinsic and extrinsic properties of the SmB 6 surface are elucidated in this manuscript, no clear indication of a trivial mechanism for the prominent surface conductivity is found.

Pressure-Resistant Intermediate Valence in the Kondo InsulatorSmB6

“…In this light, we suggest that recent observations of one-dimensional surface transport [19] and unusual magnetotransport [20] could be consistent with the existence of a strain-stabilized magnetic surface on SmB 6 . Our results demonstrate that a surface having strongly intermediate valence, as has been detected spectroscopically [52], can support magnetic order. and the lattice parameter also exhibit a smooth pressure dependence independent of the change in ground state.…”

Nesting-driven multipolar order in CeB6 from photoemission tomography

“…Moreover the material is hard and difficult to cleave, which is the usual procedure to measure single crystals. Third, hexaborides are subject to surface reconstructions and possess surface states, which might mask the bulk electronic structure 23 24 25 26 . Previous ARPES studies on CeB 6 are therefore sparse 27 28 29 .…”

SmB 6 nanoparticles: Synthesis, valence states, and magnetic properties

“…These interesting optical absorption properties are well satisfied the demand for reducing solar heat for the windows of automotives and architectures, and have also potential applying for medical care [10][11][12]. More recently, the mixed valence SmB 6 as a multi-functional * E-mail address: tegusph@imnu.edu.cn M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT hexaboride is considered the candidate material for topological Kondo insulators [13][14][15] and its optical absorption properties have become a hot research topic [16]. In addition, the SmB 6 have relatively lower work function of 3.11 eV and that makes it to be a potential thermionic emission material [17].…”