[Ca24Al28O64]4+:4e− electride ceramic realizes mechanical and electrical transport properties coordinated regulation via composite ZrO2

The [Ca 24 Al 28 O 64 ] 4+ :4e − (C12A7:e − ) electride is a conductive oxide ceramic with high injected electron concentration and low work function, but its brittleness leads to difficulty in mechanical processing and low production yield. The present work aimed at improving the mechanical properties of C12A7:e − by introducing monoclinic ZrO 2 . When the ZrO 2 content was 5 wt%, the fracture toughness increased 133% from 1.819 to 4.214 MPa m 1/2 and the flexural strength increased 116% from 15.916 to 34.469 MPa for C12A7:e − -5 wt% ZrO 2 , indicating that ZrO 2 can effectively improve the mechanical properties of C12A7:e − . The microstructure and phase analysis showed that the toughening mechanisms of ZrO 2 composite C12A7:e − contain both stress-induced phase transformation toughening and dispersion toughening of ZrO 2 particles. When the content of ZrO 2 is between 0 and 5 wt%, the injected electron concentration of C12A7:e − -ZrO 2 was maintained in the range of 2.05–2.10 × 10 21 cm −3 and illustrate excellent electrical transport properties. The study indicated that adding ZrO 2 in C12A7:e − effectively solves the problem of brittle fracture, improves the finished product rate during processing, and maintains its excellent electrical transport properties.