Hello everyone, please refer to this link for a detailed description of my work :)
Please refer to this link for a detailed visualization.
Please refer to this link for a more detailed simulation package.
The main goal is to use a publicity-accessible spin simulation code called Spirit (Müller et al) to simulate the results obtained from the paper Observation of a phase transition within the domain walls of ferromagnetic Co3Sn2S2 (Lee et al). In this paper, Lee et al suggested that "what sets this compound apart is the giant value of its dimensionless anisotropy factor, K", I want to use the code to reproduce the observation that spin transforms Bloch Wall to Linear Wall and verify if it is truly caused by giant value of dimensionless anisotropy factor. (●'◡'●)
I'm able to see a Bloch Wall
And Yes Sir! Linear Wall is also be observed
Stay Tuned for a comprehensive analysis of phase transition
In the absence of an applied magnetic field, ferromagnetic materials can be described by the following Hamiltonian:
Here,
- The single-ion magnetic anisotropy, where
$\hat{K}_{j}$ are the axes of the uniaxial anisotropies of the basis cell with the anisotropy strength$K_{j}$ . - The symmetric exchange interaction, where
$J_{ij}$ denotes the symmetric exchange energy and$\langle ij \rangle$ denotes the unique pairs of interacting spins$i$ and$j$ . - The dipolar interaction, where
$\mu_{0}$ is vacuum permeability,$\mu_{i}$ is dipole moment, and$\hat{r}_{ij}$ denotes the unit vector of the bond connecting two spins.
The main directory contains the core material used for simulation, including useful functions, documentation, and an overall usage example. Updates are still underway. Stay Tuned!
The logging folder contains the Spin Log, Magnetization Log, and Energy Log to be accessed for future reference.
This folder is a thorough analysis of the result of some parameters used for simulation. The main example folder is
By setting Anisotropy and Exchange energy both to 6.79 meV, I see clear information of Bloch Wall 😃
If dipole-dipole interaction is taken into consideration, then we should have more spins(i.e. layers of atoms) for a more accurate simulation. However, this simulation takes a very long long time(even just testing the curie temperature takes more than one day to run😒), so the folder is still under updating. Stay Tuned!
This folder contains necessary papers that could be useful for simulation. It includes example simulation, simulation theory, and Spirit documentations, etc.
This folder contains the overall spin structure with a 3D image, provided by Spirit built-in visualization tool. Example folder: Warmup Graph, Field Cool Graph, etc.
The testing folder contains unnecessary packages and code that I used only to understand the code better.