Template-free molten salt synthesis of pure and Sr-doped LaCrO3 1D nanorods with enhanced electrical transport properties

Abstract

One-dimensional (1D) nanomaterials have received a lot of attention owing to their unique structural, electrical, and optoelectrical properties. Perovskite-structured lanthanum chromite (LaCrO₃, LCO) is a well-known semiconducting material that is used as an active component or interconnect in nanoelectronics, electrochemical and optoelectronic devices. The 1D LCO nanorods are expected to show better electrical transport characteristics due to dimensional confinement in addition to the ease of integration in devices. The conventional synthetic protocols typically yield 3D nanoparticles with irregular morphologies limiting the scope of this important material. Herein, we report a template-free molten salt synthesis (MSS) method to synthesise single-crystalline 1D nanorods of LCO. The strategy was further extended to synthesise Sr²⁺-doped La_1−xSr_xCrO₃ (LSCO-10 where x = 0.1; and LSCO-20 where x = 0.2) nanorods as alkaline earth metal doping is known to enhance electrical properties. The electrical conductivity was found to be 27 mS cm⁻¹ for pure LCO nanorods, which further increased on Sr²⁺ doping to 12 640 mS cm⁻¹ (LSCO-10) and 22 700 mS cm⁻¹ (LSCO-20). The observed conductivity values are about three orders higher than those of previous reports for LCO nanoparticles with various morphologies. This work establishes the template-free MSS as a new route to access low dimensional morphologies with superior performance, which were otherwise inaccessible.