Method for measuring nonlinear susceptibility of materials

Abstract

The invention provides a method for measuring nonlinear electric susceptibility coefficient of materials, which comprises the following steps: a) scanning the surface of a sample to be measured by a scanning probe microscope with a conductive point in a lifting mode; b) measuring the change of a phase angle difference delta theta between actuating and alternating signals for driving the point to oscillateand actual oscillator signals of the point along a point bias Vt; and c) interpreting the delta theta and the Vt obtained through measurement to obtain the electric susceptibility coefficient of the sample to be measured. The method can measure the nonlinear electric susceptibility coefficient of the materials in nano range by utilizing CSPM, has important significance for researching the nonlinearity ofthe materials, is a novel means for measuring the nonlinear electric susceptibility coefficient of the materials, and can realize measurement point by point of nonuniform samples in the point curvature radiussize area and measurement in a nano area due to high resolution of the SPM.

Description

technical field [0001] The invention belongs to the technical field of surface analysis, and in particular relates to a method for measuring the nonlinear electric susceptibility coefficient of a material by using a scanning probe microscope (Scanning Probe Microscope, SPM for short) conductive tip. Background technique [0002] The long-range electrostatic interaction force between the tip and the sample can be measured by acting on the bias voltage of the conductive tip or the sample, which can be used to detect the surface charge of the sample, the surface potential, the static and dynamic properties of ferroelectric materials, and the properties of a single nanotube. electrical transport properties, etc. The tip of a general Conductive Scanning Probe Microscope (CSPM) is an irregular pyramid-shaped tip. The electric field intensity generated by the charged charge on the tip has a lot to do with the shape of the tip and the distance between the tip and the sample. For a s...

AI Technical Summary

Problems solved by technology

So far, there are many measurement methods for the physical parameters of nonlinear materials, but they are all based on the macro-scale range. For the sub-microscopic scale, especially based on the CSPM technology, there are no literature reports on the measurement of the physical parameters of nonlinear materials.

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