Related Experiment Video
Updated: Jun 23, 2026
06:53
Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Quenched-vacancy induced spin-glass order.
1Department of Physics, Dokuz Eylül University, Buca 35160, Izmir, Turkey.
Summary
Adding dilution to ferromagnetic Ising models can create a spin-glass phase. This spin-glass phase expands under dilution, impacting ferromagnetic and antiferromagnetic phases, and shows temperature reentrance.
Area of Science:
- Statistical Mechanics
- Condensed Matter Physics
- Phase Transitions
Background:
- The ferromagnetic phase of the Ising model is well-studied.
- Understanding the effects of disorder, such as bond randomness and dilution, is crucial for complex magnetic systems.
Purpose of the Study:
- To investigate the impact of quenched bond dilution on the ferromagnetic phase of a 3D Ising model.
- To determine the conditions under which a transition to a spin-glass phase occurs.
Main Methods:
- Numerically exact global renormalization-group solution.
- Analysis of a 3D hierarchical lattice model.
Main Results:
- The ferromagnetic phase transitions to a spin-glass phase with sufficient quenched bond dilution.
- The spin-glass phase expands in the phase diagram at the expense of ferromagnetic and antiferromagnetic phases.
- Reentrance behavior is observed in the ferromagnetic-spin-glass phase transition as a function of temperature.
Conclusions:
- Quenched dilution is a key factor in inducing spin-glass behavior in ferromagnetic systems.
- The findings are expected to be generalizable to other lattice structures like the cubic lattice and for site dilution.
- The study reveals complex phase diagram behavior including reentrance, influenced by dilution and temperature.
Related Concept Videos
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
01:03Atomic Nuclei: Nuclear Spin State Overview
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
01:17Spin–Spin Coupling: One-Bond Coupling
Coupling interactions are strongest between NMR-active nuclei bonded to each other, where spin information can be transmitted directly through the pair of bonding electrons. While nuclei polarize their electrons to the opposite spins, the bonding electron pair has opposite spins. Configurations with antiparallel nuclear spins are expected to be lower in energy. When coupling makes antiparallel states more favorable, J is considered to have a positive value. The one-bond coupling constant, 1J,...
01:20Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others.
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...