Mg2Si-based thermoelectric compounds with enhanced fracture toughness by introduction of dual nanoinclusions

Publication date: 15 September 2019Source: Journal of Alloys and Compounds, Volume 801Author(s): Gwansik Kim, Hyun Jun Rim, Hwijong Lee, Jeongmin Kim, Jong Wook Roh, Kyu Hyoung Lee, Wooyoung LeeAbstractDual nanoinclusions of reduced graphene oxides (rGOs) and metal nanoparticles (NPs) were introduced into Al and Bi co-doped Mg2Si thermoelectric (TE) compounds to enhance their fracture toughness (∼0.82 MPa m1/2 for pristine Mg1.96Al0.04Si0.97Bi0.03). The TE performance of Mg1.96Al0.04Si0.97Bi0.03 decreased by the introduction of nanoscale inclusions, mainly owing to the deterioration of the electronic transport properties originated from increased electron scattering. However, a significantly enhanced fracture toughness of 2.26 MPa m1/2 was achieved by the introduction of 3 vol% rGOs (∼5 nm thick and ∼3 μm wide) and 0.6 vol% Sn NPs (50–150 nm), owing to the simultaneous activation of three different inhibition mechanisms for crack propagation: bridging of cracks, sheet pullout within the crack, and deflection of crack propagation.
Source: Journal of Alloys and Compounds - Category: Chemistry Source Type: research