CN-116539658-B - Measurement method and application of thermal expansion coefficient of layered two-dimensional material surface

CN116539658BCN 116539658 BCN116539658 BCN 116539658BCN-116539658-B

Abstract

The invention provides a method for measuring the surface thermal expansion coefficient of a layered two-dimensional material and application thereof, wherein the method comprises the steps of measuring the bending stiffness delta of the layered two-dimensional material in the direction perpendicular to a plane, substituting the thermal expansion coefficient alpha bond of a chemical bond in the layered two-dimensional material into a formula (1) to obtain the surface thermal expansion coefficient alpha s ;α s ＝2α bond -50/delta (1) of the layered two-dimensional material. The invention provides a method for obtaining the thermal expansion coefficient of the two-dimensional material through conversion by combining the two test schemes for the first time. The measuring method has the advantages of simple operation, movable test data, wide coverage temperature range and stable result.

Inventors

YANG YANG
Zong Hongxiang
DING XIANGDONG

Assignees

西安交通大学

Dates

Publication Date: 20260505
Application Date: 20230504

Claims (7)

1. A method for measuring the thermal expansion coefficient of a layered two-dimensional material surface, which is characterized by comprising the following steps: Measuring bending rigidity delta of the layered two-dimensional material in a direction perpendicular to a plane, and substituting a thermal expansion coefficient alpha bond of a chemical bond in the layered two-dimensional material into a formula (1) to obtain a surface thermal expansion coefficient alpha s of the layered two-dimensional material; α s ＝2α bond –50/δ(1)。
2. the method for measuring the thermal expansion coefficient of a layered two-dimensional material surface according to claim 1, wherein the units of bending rigidity δ are eV and the units of thermal expansion coefficient are 10 -6 ·K -1 .
3. The method for measuring the thermal expansion coefficient of the layered two-dimensional material according to claim 1, wherein the flexural rigidity δ of the layered two-dimensional material in the direction perpendicular to the plane is measured by a pressurized bubbling method.
4. The method for measuring the thermal expansion coefficient of the surface of the layered two-dimensional material according to claim 1, wherein the thermal expansion coefficient α bond of the chemical bond in the layered two-dimensional material is measured by using an X-ray absorption fine structure spectrum.
5. The method for measuring the thermal expansion coefficient of the layered two-dimensional material surface according to claim 1, wherein the method specifically comprises the following steps: Preparing a layered two-dimensional material; Measuring the thermal expansion coefficient alpha bond of chemical bonds in the layered two-dimensional material by means of an X-ray absorption fine structure spectrum; transferring the layered two-dimensional material to a substrate material with small holes, and measuring the bending rigidity delta of the layered two-dimensional material in the direction perpendicular to the plane by a pressurized bubbling method; substituting the measured thermal expansion coefficient alpha bond and bending stiffness delta of the chemical bond into formula (1) to calculate to obtain the surface thermal expansion coefficient alpha s of the layered two-dimensional material; α s ＝2α bond –50/δ(1)。
6. The method for measuring the surface thermal expansion coefficient of a layered two-dimensional material according to claim 5, wherein the preparing the layered two-dimensional material comprises preparing the layered two-dimensional material by a mechanical exfoliation method, a physical vapor deposition method or a chemical vapor deposition method.
7. Use of the method for measuring the thermal expansion coefficient of a surface of a layered two-dimensional material according to any one of claims 1 to 6 in the field of measuring or evaluating the thermal expansion coefficients of different two-dimensional materials.

Description

Measurement method and application of thermal expansion coefficient of layered two-dimensional material surface Technical Field The invention relates to the technical field of measurement, in particular to a measurement method and application of a thermal expansion coefficient of a layered two-dimensional material surface. Background With the miniaturization and microminiaturization of electronic equipment and the development of flexible electronic materials, research and development of a new generation of nano functional devices are needed, and two-dimensional materials represented by graphene, black phosphane, molybdenum disulfide and the like have natural nano thickness, good flexibility and rich functional characteristics, so that the nano functional devices have great application potential. However, two-dimensional materials typically have lamellar properties, with layers often bonded in the form of stronger covalent bonds, and layers often bonded in weaker van der Waals forces. The layered characteristic determines that a laminated structure is inevitably adopted from processing preparation to application service of the two-dimensional material, so that a heterojunction between the two-dimensional material and a matrix or between different two-dimensional materials is formed, and the problem of thermal matching between different materials becomes a key problem for determining the functional characteristic of the two-dimensional material, and at the moment, the thermal expansion coefficients of the different two-dimensional materials need to be measured or estimated. The coefficient of thermal expansion is defined as the rate of change of the dimensions of a material with temperature. Therefore, for bulk materials, the principle of measuring the thermal expansion coefficient is simple, and only the dimensions (length, area, volume and the like) of the materials at different temperatures need to be measured. However, for two-dimensional materials, the thermal fluctuation of the material is huge due to the small size of the material, so that the temperature of the material is difficult to accurately measure, and the material often has a transparent state, so that the size of the material is difficult to accurately measure, and the thermal expansion coefficient of the two-dimensional material is difficult to directly measure like a bulk material. The existing method for directly measuring the thermal expansion coefficient is mainly a thermal bubbling method, namely, the suspended material is heated, the deflection change of the suspended material is measured, and then the corresponding thermal expansion coefficient is calculated. More indirect methods are used, such as raman spectroscopy, electron energy loss spectroscopy, etc., to map the temperature or size of the system with the target observed quantity, and then to obtain the thermal expansion coefficient. However, most indirect testing methods have difficulty in eliminating the effect of the substrate material on thermal expansion properties. Disclosure of Invention In order to solve the technical problems, the invention provides a measurement method and application of a thermal expansion coefficient of a layered two-dimensional material surface, and also provides a measurement method and application of a thermal expansion coefficient of a layered two-dimensional material surface. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The invention provides a method for measuring the surface thermal expansion coefficient of a layered two-dimensional material, which comprises the steps of measuring the bending stiffness delta of the layered two-dimensional material in the direction perpendicular to a plane, and substituting the thermal expansion coefficient alpha bond of a chemical bond in the layered two-dimensional material into a formula (1) to obtain the surface thermal expansion coefficient alpha s;αs＝2αbond -50/delta (1) of the layered two-dimensional material. The invention provides a method for obtaining the thermal expansion coefficient of the two-dimensional material through conversion by combining the two test schemes for the first time. Further, the flexural rigidity is given in eV and the thermal expansion coefficients are given in 10 -6·K-1. If other units are used, the coefficient of thermal expansion of the material can be estimated using this relationship after conversion. Further, the flexural rigidity delta of the layered two-dimensional material in the direction perpendicular to the plane is measured by a pressurized bubbling method. Further, the thermal expansion coefficient alpha bond of the chemical bond in the layered two-dimensional material is measured by adopting an X-ray absorption fine structure spectrum. Further, the method specifically comprises the steps of preparing a layered two-dimensional material, measuring the thermal expansion coefficient alpha bond of chemical bonds i