Influence of Electron Correlations on Magnetic Properties in Transition Metals in View of Degeneration

2009 ◽  
Vol 152-153 ◽  
pp. 555-558
Author(s):  
V.E. Shilov ◽  
E.V. Shilova
Keyword(s):  
Magnetic Properties ◽  
Spin State ◽  
Experimental Verification ◽  
Initial Segment ◽  
High Spin State ◽  
The Self ◽  
Electron Correlations ◽  
Optical Branch ◽  
Self Energy ◽  
Loop Approximation

Transition from high-spin state to low-spin state is considered in this work. The self - energy in one-loop approximation was calculated. The three – orbital periodic Anderson-Hubbard model is used to obtain an initial segment of an optical branch in view of degeneration. The possibility of experimental verification of the received result by a method of non-elastic dispersion of slow neutrons is mentioned.

scholarly journals Co-Substitution Effect in Room-Temperature Ferromagnetic Oxide Sr3.1Y0.9Co4O10.5

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2301
Author(s):  
Akihiro Tsuruta ◽  
Shuji Kawasaki ◽  
Masashi Mikami ◽  
Yoshiaki Kinemuchi ◽  
Yoshitake Masuda ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
High Spin ◽  
Spin State ◽  
Room Temperature ◽  
High Spin State ◽  
Substitution Effect ◽  
Co Substitution ◽  
Intermediate Spin ◽  
Intermediate Spin State

We investigated the Co substitution effect for the magnetic properties in room-temperature ferromagnetic oxide Sr3.1Y0.9Co4O10.5. The substituted element (Al and Ga) and low-spin state Co3+, which was changed from a high-spin or intermediate-spin state by Al or Ga substitution, reduced the Curie temperature to even 1.5 times lower than the temperature estimated from a simple dilution effect. Al3+ preferentially substituted for intermediate-spin-state Co3+ in the ferrimagnetic CoO6 layer and deteriorated the saturation magnetization of Sr3.1Y0.9Co4O10.5. By contrast, Ga3+ substituted for high-spin-state Co3+ in the CoO6 layer and/or the antiferromagnetic CoO4.25 layer and enhanced the saturation magnetization per Co ion. These results indicate that the magnetic properties of Sr3.1Y0.9Co4O10.5 can be controlled by selectively substituting for Co3+ with different spin states.

scholarly journals Steric Quenching of Mn(III) Thermal Spin Crossover: Dilution of Spin Centers in Immobilized Solutions

2022 ◽  
Vol 8 (1) ◽  
pp. 8
Author(s):  
Komala Pandurangan ◽  
Anthony B. Carter ◽  
Paulo N. Martinho ◽  
Brendan Gildea ◽  
Tibebe Lemma ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Structural Analysis ◽  
High Spin ◽  
Spin State ◽  
Spin Crossover ◽  
High Spin State ◽  
Spectroscopic Studies ◽  
Raman Spectroscopic ◽  
Spin Triplet ◽  
Structural And Magnetic Properties

Structural and magnetic properties of a new spin crossover complex [Mn(4,6-diOMe-sal2323)]+ in lattices with ClO4−, (1), NO3−, (2), BF4−, (3), CF3SO3−, (4), and Cl− (5) counterions are reported. Comparison with the magnetostructural properties of the C6, C12, C18 and C22 alkylated analogues of the ClO4− salt of [Mn(4,6-diOMe-sal2323)]+ demonstrates that alkylation effectively switches off the thermal spin crossover pathway and the amphiphilic complexes are all high spin. The spin crossover quenching in the amphiphiles is further probed by magnetic, structural and Raman spectroscopic studies of the PF6− salts of the C6, C12 and C18 complexes of a related complex [Mn(3-OMe-sal2323)]+ which confirm a preference for the high spin state in all cases. Structural analysis is used to rationalize the choice of the spin quintet form in the seven amphiphilic complexes and to highlight the non-accessibility of the smaller spin triplet form of the ion more generally in dilute environments. We suggest that lattice pressure is a requirement to stabilize the spin triplet form of Mn3+ as the low spin form is not known to exist in solution.

scholarly journals Opacity from Loops in AdS

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Alexandria Costantino ◽  
Sylvain Fichet
Keyword(s):  
Imaginary Part ◽  
Quantum Dynamics ◽  
Model Building ◽  
Asymptotic Properties ◽  
The Self ◽  
Effective Theory ◽  
Self Energy ◽  
Higher Dimensional ◽  
Timelike Region ◽  
Spectral Representations

Abstract We investigate how quantum dynamics affects the propagation of a scalar field in Lorentzian AdS. We work in momentum space, in which the propagator admits two spectral representations (denoted “conformal” and “momentum”) in addition to a closed-form one, and all have a simple split structure. Focusing on scalar bubbles, we compute the imaginary part of the self-energy ImΠ in the three representations, which involves the evaluation of seemingly very different objects. We explicitly prove their equivalence in any dimension, and derive some elementary and asymptotic properties of ImΠ.Using a WKB-like approach in the timelike region, we evaluate the propagator dressed with the imaginary part of the self-energy. We find that the dressing from loops exponentially dampens the propagator when one of the endpoints is in the IR region, rendering this region opaque to propagation. This suppression may have implications for field-theoretical model-building in AdS. We argue that in the effective theory (EFT) paradigm, opacity of the IR region induced by higher dimensional operators censors the region of EFT breakdown. This confirms earlier expectations from the literature. Specializing to AdS5, we determine a universal contribution to opacity from gravity.

scholarly journals Classical gravitational self-energy from double copy

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Gabriel Luz Almeida ◽  
Stefano Foffa ◽  
Riccardo Sturani
Keyword(s):  
Gravitational Field ◽  
Binary System ◽  
The Self ◽  
Gravitational Coupling ◽  
Leading Order ◽  
Body System ◽  
Self Energy ◽  
Composite Systems ◽  
Body Dynamics ◽  
Double Copy

Abstract We apply the classical double copy to the calculation of self-energy of composite systems with multipolar coupling to gravitational field, obtaining next-to-leading order results in the gravitational coupling GN by generalizing color to kinematics replacement rules known in literature. When applied to the multipolar description of the two-body system, the self-energy diagrams studied in this work correspond to tail processes, whose physical interpretation is of radiation being emitted by the non-relativistic source, scattered by the curvature generated by the binary system and then re-absorbed by the same source. These processes contribute to the conservative two-body dynamics and the present work represents a decisive step towards the systematic use of double copy within the multipolar post-Minkowskian expansion.

Theoretical study on the reduction reactions from solid char(N): The effect of the nearby group and the high-spin state

Energy ◽  
2019 ◽  
Vol 189 ◽  
pp. 116286 ◽  
Author(s):  
Hai Zhang ◽  
Lei Luo ◽  
Jiaxun Liu ◽  
Anyao Jiao ◽  
Jianguo Liu ◽  
...  
Keyword(s):  
High Spin ◽  
Spin State ◽  
Theoretical Study ◽  
High Spin State ◽  
Reduction Reactions
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