Structural and electrical characterization of the monolayer Kondo-lattice compound CePt${}_6$/Pt(111)

Abstract

We report the growth process, structure, and electronic states of 1 unit layer (u.l.) of a Ce-Pt intermetallic compound on Pt(111) using scanning tunneling microscopy/spectroscopy (STM/STS) and low-energy electron diffraction. An ordered $(2\times 2)$ structure was observed in the form of films or nanoislands depending on Ce dose by annealing at around 700 K. A structural model constructed from atomically resolved STM images and quasiparticle interference (QPI) patterns indicates the formation of a new surface compound 1 u.l. CePt${}_6$ on Pt(111) terminated by a Pt layer. A lateral lattice constant of the 1 u.l. CePt${}_6$ on Pt(111) is expanded from the value of a bulk CePt${}_5$ crystal to match the Pt(111) substrate. By measuring d$I$/d$V$ spectra and QPI, we observed an onset energy of the surface state found on Pt(111) above Fermi energy ($E_F$) shifts below $E_F$ on the Pt layer of the 1 u.l. CePt${}_6$ due to charge transfer from the underneath CePt${}_2$ layer. We discuss a possible two-dimensional coherent Kondo effect with the observed spectra on the 1 u.l. CePt${}_6$.

10 pages, 7 figures

References in corpus (9)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum Criticality in Heavy Fermion Metals
• Imaging the Fano Lattice to 'Hidden Order' Transition in URu2Si2
• Visualizing heavy fermions emerging in a quantum critical Kondo lattice
• Exchange interaction between single magnetic adatoms
• Hybridization, Inter-Ion Correlation, and Surface States in the Kondo Insulator SmB6
• Electron Cotunneling into a Kondo Lattice
• Theory of Scanning Tunneling Spectroscopy: from Kondo Impurities to Heavy Fermion Materials
• Kondo screening and beyond: an x-ray absorption and dichroism study of CePt${}_5$/Pt(111)