Negative thermal expansion ceramic material Sc<x>In<2-x>Mo<3>O<12> and method for preparing same

Abstract

The invention discloses a negative thermal expansion ceramic material Sc<x>In<2-x>Mo<3>O<12> and a method for preparing the same, and belongs to the field of inorganic nonmetal functional materials. The x is larger than or equal to 1.4 and is smaller than or equal to 1.6. The negative thermal expansion ceramic material Sc<x>In<2-x>Mo<3>O<12> and the method have the advantages that the negative thermal expansion ceramic material Sc<x>In<2-x>Mo<3>O<12> is made of high-purity Sc<2>O<3>, In<2>O<3> and MoO<3> which are raw materials and is prepared by the aid of solid-phase processes, oxide of the raw materials is weighed according to certain molar ratios, is subjected to ball-milling and shaping and is sintered at the temperatures of 750-1100 DEG C to obtain ceramics made of oblique-direction negative thermal expansion materials Sc<x>In<2-x>Mo<3>O<12>, and the ceramics are dense in structure and are stable in negative thermal expansion property in the temperature ranges from the room temperature to the melting point temperatures of the ceramics; for example, the linear thermal expansion coefficients of ceramics Sc<1.5>In<0.5>Mo<3>O<12> ceramics are -3.99*10<-6> / K in the temperature ranges from the room temperature to the temperatures of 700 DEG C, thermal expansion curves are nearly linear, and the ceramics Sc<1.5>In<0.5>Mo<3>O<12> are free of phase change, stable in thermal expansion property and good in negative thermal expansion property; the method for preparing the negative thermal expansion ceramic material Sc<x>In<2-x>Mo<3>O<12> is simple, is short in preparation cycle and free of pollution and is environmentally friendly, and accordingly the negative thermal expansion ceramic material Sc<x>In<2-x>Mo<3>O<12> and the method have excellent application prospects.

Description

technical field [0001] The invention belongs to the field of negative thermal expansion inorganic functional ceramic materials, in particular to a negative thermal expansion ceramic material Sc x In 2-x Mo 3 o 12 and its preparation method. Background technique [0002] Materials that "shrink with heat and expand with cold" in volume as the temperature changes are called negative thermal expansion materials. With the development of device miniaturization and aerospace technology in the fields of microelectronics, optics and micromechanics in recent years, the precise size of materials is crucial to the function of devices. The thermal stress caused by the mismatch of thermal expansion coefficients is often the main reason for device fatigue, performance degradation, failure or even fracture and shedding. The size of the device often changes due to changes in the working environment temperature, resulting in unstable performance or even failure of the device. The discov...

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Problems solved by technology

However, it is a monoclinic phase at room temperature, showing positive thermal expansion, and it transforms into an orthorhombic phase with good negative thermal expansion properties at 340 ° C, which is very unfavorable for its application. In order to make In 2 Mo 3 o 12 It shows stable negative thermal expansion performance above room temperature. Through the doping of Sc, a new type of negative thermal expansion material Sc with excellent negative thermal expansion performance is explored. x In 2-x Mo 3 o 12 , making it exhibit negative thermal expansion at room temperature and above, which is of great significance for its future practical application

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