Electrical properties of SmB$_6$ thin films prepared by pulsed laser deposition from a stoichiometric SmB$_6$ target

TL;DR

This study demonstrates successful synthesis of SmB6 thin films via pulsed laser deposition from a stoichiometric target, maintaining correct composition and exhibiting characteristic electrical properties, thus enabling further surface and bulk investigations.

Contribution

First successful demonstration of SmB6 thin film growth by PLD from a single stoichiometric target with preserved composition and electrical properties.

Findings

RBS confirmed stoichiometric composition in films

Films exhibited characteristic electrical properties of SmB6

Growth feasible on various substrates at 600°C

Abstract

Possible existence of topologically protected surface in samarium hexaboride has created a strong need for investigations allowing to distinguish between properties coming from the surface states and those originating in the (remaining) bulk. Studies of SmB6 thin films represent a favorable approach allowing well defined variations of the bulk volume that is not affected by surface states. Moreover, thin films are highly desirable for potential technology applications. However, the growth of SmB6 thin films is accompanied by technology problems, which are typically associated with maintaining the correct stoichiometry of samarium and boron. Here we present feasibility study of SmB6 thin film synthesis by pulsed laser deposition (PLD) from a single stoichiometric SmB6 target. As proved by Rutherford Backscattering Spectrometry (RBS), we succeeded to obtain the same ratio of samarium and boron in the films as that in the target. Thin films revealing characteristic electrical properties of (crystalline) SmB6 were successfully deposited on MgO, sapphire, and glass-ceramics substrates, when the substrates were kept at temperature of 600$^\circ$ C during the deposition. Performed electrical resistance studies have revealed that bulk properties of the films are only slightly affected by the substrate. Our results indicate that PLD is a suitable method for complex and intensive research of SmB6 and similar systems.