MPMSAnalyzer 0.1.15

A python program for analyzing SQUID DC raw data

MPMSAnalyzer

Table of Contents

1. Overview
2. Installation
3. Quickstart
4. Known Bugs

Overview

MPMSAnalyzer is a program to increase information gain from Magnetic Property Measurement System (SQUID) DC-Measurements (program written for MPMS 3 by Quantum Design).

MPMSAnalyzer key features:

• Subtract background data to remove magnetic influence of specimen holders ect.
• Afterwards adjust the dipol fitting curve to support very small specimens
• Exclude single points to avoid integrating bolter points
• Interpolate (background) measurements to save time for background subtraction
• Export to standard formats (csv)

Screenshot of MPMSAnalyzer: Original data with background subtracted and fit area cutted so borders do not influence the dipol fit. Every single fit can be inspected. (Used data is available in the example_data directory.)

Installation

Open the command line (Windows: Type cmd in the search) and run

pip install MPMSAnalyzer

Now you can start the MPMSAnalyzer by typing

python -m MPMSAnalyzer

Shortcut (Windows only)

If you prefer having a clickable program icon, create a shortcut like the following:

1. Create a new junction:
   
2. Enter python -m MPMSAnalyzer into the input field:
   
3. If you like, you can change the icon of the shortcut. To do so
   1. Download the MPMSAnalyzer.ico image from the doc directory.
   2. Now select the shortcut on your machine, then
   3. right click on it and open the Properties.
   4. In the Junction tab click on the Change icon button, then
   5. select the MPMSAnalyzer.ico image.

Manual installation

For manual installation download all the files, extract them and execute the Controller.py file in the MPMSAnalyzer directory to run MPMSAnalyzer.

Quickstart

Measurement

• Create new files for each $M(T)$/$M(H)$ measurement. Keep the files as short as possible. The MPMSAnalyzer supports files only if they have a $M(T)$ or a $M(H)$ measurement.
• Use the material in the sample material field in the MPMS program. If you have more probes than one use the exact definition of the probe in the sample comment field. Otherwise there will be no chance to identify your probe.

  You can use $\LaTeX{}$ code surrounded by \$'s in the title, comment, and other fields.

• If possible: Use the exact same sequence for measuring the background.

General program use

• Save the edited data right after editing. There may be crashes so do not hope for the best.
• All datapoints are divided in the Up- and the Down-Sweep. This means that all plotted data and all files will have twice the amount of datapoints than in the MPMS program.

Toolbar

• Open/Plot/Format: Open and plot a MPMS file. Select the *.rw.dat file. The *.dat file has be in the same directory and the same name to be registered automatically. If the file is not found you can select the *.dat file manually.

  Try to use both files always. The Open, the Plot and the Format commands are more less the same.

• Edit: Define the fit frame. Set the range of the raw position for the voltages to fit.
• Interpolate: Interpolate the background for a given measurement. The background of the probe has to be measured seperately. The background has to contain as much values as possible. You can increase the temperature/field steps, the last and first point should be the same like in the probe. Also try to cover all measurement ranges. This means for a $M(T)$ measurement with multiple fields record the background for all field values.
• Subtract: Subtract the background from the probe measurement. Make sure that the background file has the same length (so the same number of datapoints) like the probe measurement. If it does not have the same size use the Interpolate button.

  Try to subtract files as short as possible. The more lines in the file the longer it takes. Also the MPMS adds empty lines which may cause errors. If the files are shorter there are less empty lines.

• Export: Export the data to a file. This supports *.csv files and the MPMS *.rw.dat and the *.dat files. *.csv files are recommended.

Inspect and corect data

• Use double click on a datapoint of a measurement to open the fits. There you can see the recorded data and the fit. The subtracted background data will also be displayed there if you used some.
• Use the ... button for getting more information about each datapoint.
• Change the fit constants in the constants.py if the fit was not successfully.
• Remember to use the Edit Tool for specifying the fit frame.

  If background has been subtracted, there is the probe (index) and the probe (position). They should be always congruent.

Exporting

• Use the *.csv format for exporting if possible.
• Images of the plots can be created by left click and Save in the graph or in the graph window toolbar.

Known Bugs

• The Plot tool opens even if the file has been opened with another tool.

  Solution: Simply close the plot tool.

• If the files are very large or the wrong running variable has been choosen, the Format tool crashes.

  Solution: Decrease the filesize or use the correct running variable.

• Sometimes the background will be used as the probe right after opening the background file.

  Solution: Check if the probe and the background files are the correct files. If not select them again.