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Landau's theory of second-order phase transitions and its application to ferromagnetism
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In this paper, a comparison between the theory of second-order phase transitions in terms of Landau's original approach of minimizing the thermodynamic potential and the established group-theoretical approach, which is derived from the general thermodynamical approach is made.Abstract:
A detailed comparison is made between the theory of second-order phase transitions in terms of Landau's original approach of minimizing the thermodynamical potential and in terms of the established group-theoretical approach, which is derived from the general thermodynamical approach. It is shown that the two approaches are not equivalent and a number of spurious features are identified in the existing accounts of the group-theoretical criteria. Thus, minimization of the thermodynamic potential frequently gives some additional information which could not be obtained from the group-theoretical approach.read more
Citations
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Thermodynamic analysis of the effect of magnetic ordering on miscibility gaps in the Fe−Ti cubic and rhombohedral oxide minerals and the Fe−Ti oxide geothermometer
TL;DR: In this article, the effects of long-range magnetic order on the thermodynamic properties of magnetite (Fe3O4), hematite-ulvospinel (Fe2TiO4) and hematitic oxide geothermometer were investigated.
Journal ArticleDOI
Structural phase transitions in crystals with P63/mmc symmetry
TL;DR: In this article, a study of the possible phase symmetries derived from a prototype phase with space group P63/mmc (D6h4) has been performed.
Journal ArticleDOI
Analysis of magnetic structures of iron nitrides by Landau's theory of second-order phase transitions
TL;DR: In this article, the magnetization direction of ǫ-Fe3N must be parallel to the c-axis of the hexagonal structure, which may conclude the debates on the easy axes of Ã-Fe 3N in this field.
Journal ArticleDOI
A comment on the chain subduction criterion
TL;DR: In this article, the authors argue that a procedure to replace the Landau thermodynamic method should be based on the use of Ascher's maximality principle, together with further restrictions coming from the minimisation of the thermodynamic potential.
Journal ArticleDOI
Little groups of irreps of O(3), SO(3), and the infinite axial subgroups
M J Linehan,G E Stedman +1 more
TL;DR: In this paper, a new chain criterion for the determination of little groups is presented, which distinguishes massive irrep basis functions and allows for multiple branching paths; consequently, it is suitable for application to Lie groups.
References
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Book
Electrodynamics of continuous media
TL;DR: In this article, the propagation of electromagnetic waves and X-ray diffraction of X rays in crystals are discussed. But they do not consider the effects of superconductivity on superconducting conductors.
Book
The mathematical theory of symmetry in solids : representation theory for point groups and space groups
TL;DR: In this article, the authors present the double-valued representations of the 32 point groups and the 230 space groups, as well as a single-valued representation of the space groups.
Journal ArticleDOI
Magnetic Structure of Mn 4 N-Type Compounds
TL;DR: In this article, a series of N-type compounds have been investigated by means of magnetic saturation measurements and neutron diffraction experiments, and the results are explicable in terms of a model in which nitrogen acts as an electron donor and the various local environments cause differing energy level splittings of the Mn atoms.
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Simplified Theory of Symmetry Change in Second-Order Phase Transitions: Application to V 3 Si
TL;DR: In this article, a simplification of the Landau theory was proposed to predict compatible space groups in second-order phase transitions, and applied to the Si transition to predict that the lower symmetry space group is either {C}_{4v}}^{7}P4\mathrm{mc}$ or {D}_{2d}}^{5}P\overline{4}m2}.
Journal ArticleDOI
Magnetic Structure of Mn 4 N
TL;DR: In this paper, the magnetic structure of the cubic unit cell with Mn at the corner and face centers and N at the body center was determined by neutron diffraction from powders.