Near-zero thermal expansion of In _{2(1− x )} (HfMg) _x Mo ₃ O ₁₂ with tailored phase transition

Abstract

Solid solutions of In 2(1−x) (HfMg) x Mo 3 O 12 are synthesized by solid state reaction with the aim to reduce the phase transition temperature of In 2 Mo 3 O 12 and improve its thermal expansion property. The effects of (HfMg) 6+ incorporation on the phase transition and thermal expansion are investigated. It is shown that the monoclinic-to-orthorhombic phase transition temperature obviously decreases and the coefficient of thermal expansion (CTE) of the orthorhombic becomes less negative and approaches to zero with increasing the content of (HfMg) 6+ . A near zero thermal expansion covering the case at room temperature (RT) is achieved for the solid solutions with x ≥ 0.85, implying potential applications of this material in many fields.

Near-Zero Thermal Expansion and Phase Transitions in HfMg1−xZnxMo3O12

“…In recent years, a number of novel NTE materials have been designed based on the basic structure of A 2 M 3 O 12 family, including those with a general formula ABM 3 O 12 where A is tetravalent Hf 4+ or Zr 4+ and B is bivalent cation Mg 2+ or Mn 2+ , and M is W or Mo or a combination of them (Suzuki and Omote, 2004; Baiz et al, 2008; Gindhart et al, 2008; Marinkovic et al, 2008; Song et al, 2013; Li et al, 2014, 2016, 2017; Ge et al, 2016a; Liu et al, 2018) and those with a formula ABM 2 XO 12 where A and M are the same as in ABM 3 O 12 , B is a trivalent cation and X is P 5+ or V 5+ (Chen et al, 2016; Cheng et al, 2016b, 2017; Ge et al, 2016b,c). The most distinct characteristics of the materials with formula ABM 2 XO 12 are that they exhibit NTE over a wide temperature range and intense photoluminescence in the visible range.…”

Negative thermal expansion and photoluminescence in solid solution (HfSc)0.83W2.25P0.83O12–δ

“…With such substitutions, thermal expansions and other physical properties can be tailored and even near zero thermal expansion materials can be designed. [26,27] Particularly, the success in the syntheses of ABM 3 O 12 (A = Zr, Hf; B = Mg, Mn; M = W, Mo), [28][29][30][31][32][33][34] and even more recently ABM 2 XO 12 (A = Zr, Hf; B = Sc; M = W, Mo; X = P, V) [35][36][37][38] have enriched the members of NTE materials as well as their functions such as high ionic conductivity [39] and intense photoluminescence (PL). [35][36][37][38] Most of the A 2 M 3 O 12 family of materials either exhibit monoclinic-to-orthorhombic phase tran-sition (with smaller A 3+ cation) well above room temperature (RT) or are highly hygroscopic (with larger A 3+ cation) and their NTEs are observed only above the phase transition temperature or after the complete removal of crystal water.…”