Method for measuring and calculating magnetic field induced phase transition temperature shift in variable magnetic martensite phase change Heusler alloy

Abstract

The invention discloses a method for measuring and calculating the magnetic field induced phase transition temperature shift in a variable magnetic martensite phase change Heusler alloy. The method comprises the following steps: 1) placing a sample in a vibrating sample magnetometer, and vacuumizing the vibrating sample magnetometer; 2) loading the vibrating sample magnetometer into the magnetic field HM of the magnetic field induced martensite phase change size, and waiting for the magnetic field to be stable; 3) setting a test temperature in the magnetic field determined in step 2), settingcontinuous field sweep under the magnetic field from -HM to 0 and from 0 to HM, and testing the R-H curve of the resistance R of the sample with the change of the magnetic filed; 4) changing the testtemperature under the magnetic field determined in the step 2), and repeating the test process in step 3); and 5) calculating the size of the magnetic field induced phase transition temperature shiftat different temperatures according to the R-H curves at all temperatures, obtained in step 4). The macroscopic resistance change caused by the different characteristics of the magnetic transport property in every phase change stage during phase change is used to analyze and calculate the phase change temperature shift; and the method has the advantages of few required test data, simple calculation process and reliable result.

Description

technical field [0001] The invention belongs to the field of material physics, and in particular relates to a method for measuring and calculating the magnetic field-induced phase transition temperature shift in the magnetic field martensitic phase transition Hassler alloy. Background technique [0002] Magnetic field-induced phase transformation means that under the action of an external magnetic field, the alloy transforms from a high-symmetry cubic austenite phase to a low-symmetry martensite phase, resulting in a structural change with displacement and no diffusion. The driving force is the parent phase Zeeman energy difference between austenite and martensite phases. When the magnitude of the applied magnetic field is changed, the phase transition temperature of the alloy will move accordingly. In previous studies, there are two methods to determine the temperature shift of magnetically induced phase transition. One is to read the data from the test results of the magn...

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This method requires a lot of test data and complex calculations

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