Questions tagged [magnetism]

For questions about magnetic systems and materials

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9
votes
1answer
82 views

How to automatically plot atomic structures with magnetic moments?

I work with magnetic materials and I haven't found a way to automatically plot structures with their corresponding magnetic moments. For this specific project I am using VASP. I am trying to plot ...
10
votes
1answer
47 views

Spin density in systems with non-collinear magnetism using VASP

I have recently been working with non-collinear antiferromagnetic systems. I understand that, in order to obtain spin density, one must obtain the electron density in one configuration of spin and ...
14
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3answers
979 views

Magnetism and Topology

Does anyone know if magnetism and topological insulating behavior coexist in a material? If yes, can someone refer to a recent work?
5
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1answer
63 views

What measured quantity can be associated to the value of the J parameter in the Heisengerg/Ising hamiltonians?

This question is related to other one here in the MatterModelingSE: Is it possible to calculate/estimate the value of the J parameter to be used in the Heisengerg/Ising hamiltonians? Here J is the ...
5
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0answers
65 views

Is it possible to calculate/estimate the value of the J parameter to be used in the Heisengerg/Ising hamiltonians?

Studying magnetic systems, two frequently used approximations are the Heisenberg and Ising models (a discussion about these approximations can be read here): \begin{equation} \tag{Heisenberg} \hat{H}...
13
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1answer
71 views

How accurately are magnetic effects treated in *ab initio* methods?

I am a condensed matter theorist and I mostly use quantum Monte Carlo methods. I use models like the Heisenberg model, an represent an extreme simplification of real materials to just localized spin ...
4
votes
1answer
157 views

How is the material $\ce{\alpha-NaMnO2}$ pronounced? [closed]

I am a theoretical physicist, so I am not very familiar with chemical names. The material I am interested in is $\ce{\alpha-NaMnO2}$. Would that be pronounced alpha sodium manganese dioxide? Is it ...
12
votes
1answer
179 views

Is Heisenberg model or in its simplier form Ising model a good approximation to study magnetic systems?

Heisenberg model $$\hat{H}=-\sum_{\langle i j\rangle}J\hat{S}_i\hat{S}_j$$ And in its simplified version, the Ising model $$\hat{H}=-\sum_{\langle ij\rangle}J\hat{S}_i^z\hat{S}_j^z$$ are widely ...
22
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3answers
139 views

What are examples of materials that closely correspond to the Heisenberg model?

I use the antiferromagnetic Heisenberg model all the time: $ H = J \sum \limits_{\langle i,j \rangle} \vec S_i \cdot \vec S_j$ What are some examples of materials that are well-described by this ...
12
votes
2answers
45 views

How does magnetic anisotropy cause stable long range magnetic ordering in quasi-one-dimensional solids?

According to Mermin-Wagner theorem ferro/antiferromagnetic ordering cannot occur in ideal one dimensional systems. However there exists quasi-one-dimensional ferromagnetic materials attributing its ...
16
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1answer
35 views

Does the thermal evolution of molecular structures critically affect the validity of the calculated magnetic anisotropy?

This is a particular aspect I'm interested in, from the more generic question "Does the thermal evolution of chemical structures critically affect the validity of the calculated physical properties?". ...
15
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2answers
159 views

Is there any good review paper on the density matrix renormalization group (DMRG) method?

I would appreciate if someone could recommend me good review literature on the density matrix renormalization group (DMRG) method, especially for magnetic systems.
19
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1answer
158 views

Calculation of the relative energies in a Spin Crossover material

Spin Crossover (SCO) complexes are a particular type of molecular entities which are usually formed by a metal ion (general $\ce{Fe(II)}$ or $\ce{Co(III)}$) complexed by several ligands with donor N ...
13
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1answer
87 views

How to model phase transitions at critical regions in a magnetic system?

Is there any first principle method available to study phase transitions at the critical region for ferromagnetism (FM) or antiferromagnetism (AFM)?
17
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1answer
69 views

Best partial atomic charges estimate for crystal field purposes?

The estimates for partial atomic charges start with the very simple Mulliken analysis, which we all study in class, but which is known to be very limited. Beyond this, there is a range of ...
15
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1answer
79 views

How to evaluate spin exchange parameters of a magnetic material using DFT?

I think we have to calculate total energies using different FM, AFM configurations and solve a set of linear equations. How to arrive at the set of equations for any given structure? An example from ...