Nagdsi2o6 – a Novel Antiferromagnetic Silicate with Vierer Chain Structure

Ceramics based on pyroxenes and pyroxenoids present new pathways towards diverse functional materials. In this study, a novel sodium gadolinium pyroxene with NaGdSi 2 O 6 composition was successfully synthesised via a chelation-polymerisation based sol-gel method and its crystal structure was determined by Rietveld refined synchrotron X-ray powder diffraction. NaGdSi 2 O 6 crystallises in monoclinic symmetry with space group P 2 1 /c and unit cell parameters of a = 5.44069(8) Å, b = 13.83410(17) Å, c = 7.66897(9) Å and β = 109.9929(6)° (Z = 4). The structure has been identified to be an inosilicate with a strongly undulated single tetrahedral chain along c with a chain periodicity of 4 ( Vierer chain). Vierer chain-type NaGdSi 2 O 6 shows antiferromagnetic ordering below 45 K, with a transition temperature that is noticeably higher than that reported for structurally related multiferroic and magnetoelectric materials, indicating its potential in respective applications.