Studies On The Characteristic Parallelogram Grid In Square System And Hexagonal Crystal System And The Improvement Of The Electron Diffraction Pattern Demarcating

With the development of the modern science and technology,it's requested that the material worker can provide the precise material information in time.Demarcating the electron diffraction pattern accurately is the important method of obtaining the material structure information,researching the material microscopic organization and the crystal structure of the solid sample.Therefore every material worker should master the accurate methods of demarcating the electron diffraction pattern,if possible.Based on the predecessor's foundation,this article improve on demarcating of the electron diffraction pattern of 7 crystalline systems,especially hexagonal system, square system,The research works as follows:First,we elaborated the significance and necessity of the electron diffraction pattern and the reasons of this topic.At the same time the principle and relevant knowledge of the diffraction spectrum were introduced.We respectively studied the demarcate methods of electron diffraction pattern in the systems.A new scale method for the measure of the electron diffraction pattern is provided.Secondly,we studied the conversion principle of 40 basic diffraction patterns on square crystal system and hexagonal crystal system.Then we also studied the impacts of quartet on square crystal system and hexagonal crystal system.We chose(c/a)~2 as the impact parameter,whose values as the interval turning points.At the same time,we introduced the index of cubic diffraction pattern as the index of square crystal system and hexagonal crystal system.And then we analyzed conversion interval and set the reciprocal vector to every interval,then we proved the results.On this basis,we summarized the law of the changes of the characteristic parallelogram grid of 40 basic diffraction pattern of the square crystal system and hexagonal crystal system,analyzed the changing law of the same diffraction pattern vary with the c / a,discussed the differences and relations of the characteristic parallelogram grid between cubic system and square,hexagonal crystal system and plotted the graphics at every range.On the basis of supplement and correction a large number of previous works,we studied and worked out a unified basic characteristic parallelogram grid(include the graphics of diffraction pattern) of the square system and hexagonal crystal system.It needn't look around for the characteristic parallelogram grid that has a specific c / a value for demarcating,which was always failed before.Thus this is a very significant work.At the same time the characteristic parallelogram grid is divided into 21 ranges in square system and 12 ranges in hexagonal crystal system and each interval has a corresponding the characteristic parallelogram grid.It will be useful to demarcating in the square crystal system and hexagonal crystal system.Again,by the analysis on the characteristic parallelogram table of the square crystal system and hexagonal crystal system of quartet impacts,we have brought forward Matlab method to calibrate the non-cubic system electron diffraction pattern.We compiled the program in Matlab for the characteristic parallelogram grid of the electron diffraction pattern non- cubic crystal systems.Then because of various cause,it may be a few change in the lengths of diffraction photographs,whose proportion may have not been changed.Therefore the methods of use the CAD software to measure the size was proposed.We have measured the lengths of diffraction photographs,in CAD software.Finally,we chosen several special examples and calibrated the diffraction pattern. Last we verified the feasibility of the characteristic parallelogram grid.