Conductive Mg-P co-doped Cu2V2O7-graphene negative thermal expansion material and preparation method thereof

Abstract

The invention relates to the technical field of negative thermal expansion materials, and discloses a conductive Mg-P co-doped Cu2V2O7-graphene negative thermal expansion material and a preparation method thereof. The conductive Mg-P co-doped Cu2V2O7-graphene negative thermal expansion material comprises the following formula raw materials: graphene oxide, CuO, MgO, V2O5 and NH4H2PO4. According tothe conductive Mg-P co-doped Cu2V2O7-graphene negative thermal expansion material and the preparation method thereof, Cu2V2O7 has a stable linear negative thermal expansion coefficient, a centrosymmetric monoclinic phase structure is formed by doping Cu2V2O7 with Mg, under temperature variation, the Mg-O bond generates a vibration effect, the internal coupling effect of the Cu2V2O7 crystal is improved, a linear chain-shaped monoclinic phase in the crystal is destroyed, oxygen atoms form a new arrangement in the crystal lattice, local collapse occurs, the Cu2V2O7 is enabled to show a negativethermal expansion phenomenon, P atoms replace part of V atoms, the grain size of Cu2V2O7 is reduced, the bond energy of P-O bonds is larger than that of V-O bonds, stress in Cu2V2O7 lattices is reduced, lattice distortion is reduced, the electron scattering probability and the high-frequency dielectric constant are reduced, and therefore the conductivity of Cu2V2O7 is enhanced.

Description

technical field [0001] The invention relates to the technical field of negative thermal expansion materials, in particular to a conductive Mg-P co-doped Cu 2 V 2 o 7 -Graphene negative thermal expansion material and its preparation method. Background technique [0002] Thermal expansion and contraction are a natural phenomenon of most materials. During application, materials will undergo volumetric deformation due to temperature changes. Devices made of different materials will generate heat due to the mismatch of expansion coefficients under temperature changes. Stress reduces the physical properties of the device. Negative thermal expansion refers to compounds whose average linear expansion coefficient or volume expansion coefficient is negative within a certain temperature range. Negative thermal expansion materials expand with cold and shrink with heat under temperature changes, and the thermal expansion coefficient has a superposition Negative thermal expansion mater...

AI Technical Summary

Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the present invention provides a conductive Mg-P co-doped Cu 2 V 2 o 7 -Graphene negative thermal expansion material and its preparation method solve the problem of high phase transition temperature and poor expansion performance of negative thermal expansion material, and solve the problem of low electrical conductivity and low electrical conductivity of negative thermal expansion material at the same time