2016/03/30

Magnetic moment distribution analysis software with
SVD method for MNPs (Version 1.00E) Basic manual
Kyushu University
Faculty of Information Science and Electrical Engineering
T. Sasayama, T. Yoshida, and K. Enpuku

1. Outline
This software can obtain the distribution of the magnetic moment of nanoparticles (MNPs) byusing the singular value decomposition (SVD) method. Furthermore, this software can obtain thedistributions of the particle size of MNPs, and the M-H curve that is reconstructed from thedistributions of the magnetic moment (Figure 1). In the calculation, MNPs are assumed to besuperparamagnetic, and the interference between MNPs are ignored.

Fig. 1. Overview of the analysis software2. System requirements
MATLAB Runtime (MATLAB R2014b)(Checked environment: Windows 7 (64 bit), Windows Server 2008 R2 Enterprise)
MATLAB Runtime can be downloaded from below.
http://www.mathworks.com/products/compiler/mcr/

3. Install
Download the file “MH_analysis32e.exe” (for 32 bit OS) or “MH_analysis64e.exe” (for 64 bitOS) and execute it

4. Uninstall
Only delete the file “MH_analysis32e.exe” or “MH_analysis64e.exe”5. Usage rules
5.1 Outline
1) Analysis setting
Click the “File select…” button and select the M-H curve data file (CSV format), or manuallytype the file name of the data file. Subsequently, set the analysis parameters and analysis conditions.
(The detail is described in Section 5.3).
2) Viewer setting
Set the display method of the results. (The detail is described in Section 5.4).
3) Analysis
Click the “Analyze” button. If ”Pop up” button below figures is clicked, the figure show in theother window. If ”Save CSV” button is clicked, the CSV data of the graph can be exported.
5.2 The data format of the M-H curveThis software can read the M-H curve data saved as CSV format. First column is the magnetic
field (Unit: T), and second column is magnetization (Unit: A/m) (Figure 2). The M-H curve data in
the first quadrant should be contained, and M and H should be in ascending order*. Both exponential
notation and floating-point notation can be used.
*The negative values of M and H are ignored.

e.g. MH_resovist.csv
2.35E-05,1076
0.00012249,5622.7
0.00019177,8771.9.
.
.
5, 364000
Fig. 2. The data format of the M-H curve
5.3 Analysis parameter and condition- Analysis range of the magnetic moment“Auto” radio button
Automatically calculate the range of the magnetic moment using the maximum magnetic field
𝐻max and minimum magnetic field 𝐻min (in the assumption that 𝐻min ≤ 1 T) as follows:
Minimum of the magnetic moment; 𝑚min =𝑘𝐵 𝑇 1∙
𝐻max 𝛼Maximum of the magnetic moment; 𝑚max =𝑘𝐵 𝑇∙𝛼𝐻min𝑘𝐵 : Boltzmann constant (1.38 × 10-23 J/K)
𝑇: Absolute temperature (𝑇 = 300 K)
𝛼: Margin (default: 1)“Manual” radio button
Automatically set the range of the magnetic moment.
- Division number of magnetic moment
Determine the division number of the magnetic moment 𝐾, and calculate the calculation points ofmagnetic moments as follows:𝑚max (𝑘−1)/(𝐾−1)
𝑚𝑘 = 𝑚min (), 𝑘 = 1, 2, … , 𝐾
𝑚min- The number of singular values

Set the number of singular values for calculation. In general, as the number becomes larger, themore accurate result would be obtained. However, if the number is too large, the numericalcalculation becomes unstable. Therefore, an appropriate number should be selected.
- Correct M-H curve at saturation part
Correct the gradient at the highest magnetic field to 0 under the assumption that the M-H curve
saturates at this point.
𝑀new (𝐻) = 𝑀old (𝐻) − 𝐻 ∙d𝑀old|
d𝐻 𝐻=𝐻max

5.4 View- Ignore negative number
The minus values that are obtained from the distribution calculation becomes 0.
- Plot a semi-log graph of M-H curve
Choose semi log scale or not in the M-H curve graph.

6. license agreement
This software is free software, but copyright subsists in Teruyoshi Sasayama, Takashi Yoshida,and Keiji Enpuku (Kyushu University, Japan). We do not bear all responsibility for the damage that
we occurred by installation, use of this software.

7. Development Environment
Windows Server 2008 R2 Enterprise
MATLAB R2014b (8.4) 32 bit/64 bit

8. Contact information
Kyushu University
Faculty of Information Science and Electrical Engineering
Teruyoshi Sasayama
E:mail: sasayama@sc.kyushu-u.ac.jp