Near-zero thermal expansion of GeNb18O47 ceramic.

Near-zero thermal expansion (NZTE) materials have important scientific significance and several potential applications. In this work, a NZTE GeNb 18 O 47 ceramic has been successfully synthesized by the solid-state method, and its phase, structure, expansion properties, and NZTE mechanism were investigated. Results show that the pure phase GeNb 18 O 47 ceramic is successfully obtained, and the crystal structure is composed of NbO 6 octahedron and Nb/GeO 4 tetrahedron. GeNb 18 O 47 shows a near-zero linear coefficient of thermal expansion (CTE) of 1.23 × 10−6 °C−1 (−100–400 °C), which is caused by negative thermal expansion (NTE) originating from the rotational coupling of NbO 6 octahedron and Nb/GeO 4 tetrahedron. In addition, GeNb 18 O 47 is a NZTE semiconductor with a band gap of 3.05 eV, which has great application value in integrated circuits, and chip manufacturing. [ABSTRACT FROM AUTHOR]