DOI: 10.5281/zenodo.12210742
title: X-ray Diffraction Data Investigating Charge Density Waves in CsV3Sb5

description: ## Description of DFXM data on CsV3Sb5 collected at 6 ID-C of the Advanced Photon Source of Argonne National Lab ##

Overview

This repository contains darkfield X-ray microscopy images of CsV3Sb5 collected at the (1/2 1/2 1/4), (1/2 1/2 1/2), (1 1 2), and (2 2 0) Bragg peaks. The experiment was conducted at Sector 6-ID-C of the Advanced Photon Source (APS) at Argonne National Laboratory in March of 2023. Corresponding APS beamline scientist: Zahir Islam

# Data Structure

The data is labeled with a prefix to establish the author, experiment type, and experiment date:

    JPlumb-DFXM-Mar2023

Within each experimental folder, there are several subdirectories that contain relevant experimental files:

    "data" Folder:        Contains subfolders labeled by scan numbers in the format S### (e.g., S001, S002).        Raw data is collected and stored as 16-bit grayscale TIFF images.        Each scan represents either a single rocking curve imaging (RCI) scan, with a stack of images that were taken at various theta positions for a given sample location and two theta Bragg angle, or a time series scan that contains a stack of images taken over time, at a static theta position, and with variying sample temperature.     See Scan Group description below to learn which type of scan each folder represents.

    "logs" Folder:        Contains experimental logbooks.

    "structureFiles" Folder:        Contains .cif files with lattice parameters of different material structures (alpha and beta phases of NaMnO2).

    "referenceImages" Folder:        Includes optical microscope images of the sample in the as-measured state for reference.

    "motors" Folder:        Contains CSV files corresponding to each scan folder. These files include motor positions (theta, two-theta, XYZ) and other relevant experimental parameters.

    "scripts" Folder:        Contains basic analysis scripts for different scan groupings. Scans are grouped based on similarities and the intent behind their measurements.

    "cryostatData" Folder:        Contains data from the cryostat, recording sample temperature at various times throughout the experiment.

    "results" Folder:        Contains pre-processed maximum intensity projection images for each scan, providing a quick overview of the collected data.

December 2023 ExperimentScan Groups

Scan Group A:    hkl - (0.5, 0.5, 0.25)    # of Scans - 1    Scan #s - 1    Temperature - 3.2 K    Exposure Time - 10 seconds    X-ray Energy - 20 keV    Total Magnification - 26x    Effective Pixel Size - 2.115 um/pixel    Description - Single scan used for quick code testing.

Scan Group B:    hkl - (0.5, 0.5, 0.25)    # of Scans - 121    Scan #s - 1 to 121    Temperature - 3.2 K    Exposure Time - 10 seconds    X-ray Energy - 20 keV    Total Magnification - 26x    Effective Pixel Size - 2.115 um/pixel    Description - 0.25L peak RCI scans collected over an array of sample locations 

Scan Group C:    hkl - (0.5, 0.5, 0.5)    # of Scans - 121    Scan #s - 122 to 242    Temperature - 3.2 K    Exposure Time - 10 seconds    X-ray Energy - 20 keV    Total Magnification - 26x    Effective Pixel Size - 2.115 um/pixel    Description - 0.5L peak RCI scans collected over an array of sample locations

Scan Group D:    hkl - (1, 1, 2)    # of Scans - 1    Scan #s - 243    Temperature - 3.2 K    Exposure Time - 25 seconds    X-ray Energy - 20 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - High-resolution, fine RCI of structural peak

Scan Group E:    hkl - (2, 2, 0)    # of Scans - 1    Scan #s - 244    Temperature - 3.2 K    Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - High-resolution, fine RCI of structural peak

Scan Group F:    hkl - (2, 2, 0)    # of Scans - 3    Scan #s - 245 to 247    Temperature - 3.2 K    Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Coarse RCI of structural peak taken at 3 x positions at 3.2 K

Scan Group G:    hkl - (2, 2, 0)    # of Scans - 3    Scan #s - 248 to 250    Temperature - 87 K    Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Coarse RCI of structural peak taken at 3 x positions at 87 K

Scan Group H:    hkl - (2, 2, 0)    # of Scans - 3    Scan #s - 251 to 253    Temperature - 120 K    Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Coarse RCI of structural peak taken at 3 x positions at 120 K

Scan Group I:    hkl - (2, 2, 0)    # of Scans - 6    Scan #s - 254 to 259    Temperature - 93 K, 94 K, 94.1 K, 94.2 K, 94.3 K, 94.4 K    Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Coarse RCI taken at various temperatures through the transition (warming)

Scan Group J:    hkl - (2, 2, 0)    # of Scans - 1    Scan #s -     Temperature -     Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Static theta images taken continuously during warming from 89.4 K and up

Scan Group K:    hkl - (2, 2, 0)    # of Scans - 1    Scan #s -     Temperature -     Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Static theta images taken continuously during warming from 96 K and up

Scan Group L:    hkl - (2, 2, 0)    # of Scans - 1    Scan #s -     Temperature -     Exposure Time - 5 seconds    X-ray Energy - 22 keV    Total Magnification - 130x    Effective Pixel Size - 0.050 um/pixel    Description - Static theta images taken continuously during warming from 126 K and up

# Data Processing and Analysis

Standard DFXM data processing involves fitting a Gaussian curve to the theta-dependent intensity curve of each pixel in a rocking curve imaging scan. Plotting various gaussian fit parameters for each pixel creates parameter maps that highlight different sources of contrast.

Basic analysis scripts (ex. MR23_SGA_basicAnalysis.py) are included for all scan groups in this repository. All analysis is done in Python 3, using various free packages and self-defined scripts are stored in a sub folder named DiffractionMaster. The code is updated as of June 2024.

# Contact Information

For any questions or further information, please contact:

    Jayden C. Plumb: jaydencplumb@gmail.com

This dataset and associated documentation are part of research conducted at the Advanced Photon Source, Argonne National Laboratory and funded through the National Science Foundation and Department of Energy and under the supervision of host institution UC Santa Barbara. Please cite appropriately if used in your work.

 

## Description of HDRM data on CsV3Sb5 collected at ID4B QM2 of the Cornell High Energy Synchrotron Source ##

Overview

This repository also contains high dynamic range mapping analysis data of CsV3Sb5 collected in the 35 K to 300 K range at different cooling rates. The experiment was conducted at the QM2 beamline of the Cornell High Energy Synchrotron Source (CHESS) in February of 2023. Corresponding CHESS beamline scientist: Suchi Sarker.X-TEC machine learning algorithm was perform by Krishnanand  Mallayya. Magnetic characterization accompaning the diffraction data on three samples of the batch was performed by Andrea Capa Salinas at the Materials Research Lab's Low Temperature facilities at UC Santa Barbara.

# Data structure and analysis

"HDRM_Repository_Data" folder contains both: X-TEC analysis of HDRM data, and magnetization data.

.txt files have the naming:

"CrystalX_Fast/Slow_cool_CDW" and correspond to X-TEC analysis data with straightforward naming. Each can have up to four columns. Column objects are:

T (K): Temperature2x2x2:  Cluster average intensity for a half-type peaks whose average intensity tracks a similar temperature-dependent trajectory2x2x2+2x2x4: Cluster average intensity for a half-type peaks mixed with quarter-type peaks whose average intensity tracks a similar temperature-dependent trajectory.

.dat files have the naming:

"GP-CVS-1-X-mass(mg)_FC/ZFC-field(Oe)" and have the standard Quantum Design MPMS3 data file format. We extract "Temperature (K)", "Magnetic Field (Oe)" and "Moment (emu)" to calculate magnetic susceptibility and volumetric susceptibility of three samples in the batch used for HDRM and DFXM experiments.