Controlling crystal cleavage in Focused Ion Beam shaped specimens for surface spectroscopy

Abstract

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM). Both require atomically clean and flat crystal surfaces which traditionally are prepared by in-situ mechanical cleaving in ultrahigh vacuum chambers. We present a new approach that addresses three main issues of the current state-of-the-art methods: 1) Cleaving is a highly stochastic and thus inefficient process; 2) Fracture processes are governed by the bonds in a bulk crystal, and many materials and surfaces simply do not cleave; 3) The location of the cleave is random, preventing data collection at specified regions of interest. Our new workflow is based on Focused Ion Beam (FIB) machining of micro-stress lenses in which shape (rather than crystalline) anisotropy dictates the plane of cleavage, which can be placed at a specific target layer. As proof-of-principle we show ARPES results from micro-cleaves of Sr${}_2$RuO${}_4$ along the ac plane and from two surface orientations of SrTiO${}_3$, a notoriously difficult to cleave cubic perovskite.

References in corpus (12)

• Scanning tunneling spectroscopy of high-temperature superconductors
• Unveiling a two-dimensional electron gas with universal subbands at the surface of SrTiO3
• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• Creation and control of a two-dimensional electron liquid at the bare SrTiO3 surface
• Strong spin-orbit coupling effects on the Fermi surface of Sr2RuO4 and Sr2RhO4
• Discovery of switchable weak topological insulator state in quasi-one-dimensional bismuth iodide
• A facility for the analysis of the electronic structures of solids and their surfaces by synchrotron radiation photoelectron spectroscopy
• Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen
• Direct Observation of a Uniaxial Stress-driven Lifshitz Transition in Sr${}_2$RuO${}_4$
• In-situ strain-tuning of the metal-insulator-transition of Ca${}_2$RuO${}_4$ in angle-resolved photoemission experiments
• Incipient ferroelectricity: A route towards bulk-terminated SrTiO3
• Device for in-situ cleaving of hard crystals

Cited by in corpus (2)

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