scholarly journals Evidence of symmetry lowering in antiferromagnetic metal TmB12 with dynamic charge stripes

2021 ◽  
Author(s):  
Andrey Azarevich ◽  
Vladimir Glushkov ◽  
Sergey Demishev ◽  
Aleksey Bogach ◽  
Valerii Voronov ◽  
...  
Keyword(s):  
Phase Diagrams ◽  
Magnetic Moments ◽  
Density Wave ◽  
Spin Density Wave ◽  
Spin Fluctuations ◽  
Carrier Scattering ◽  
Dynamic Charge ◽  
Density Dynamic ◽  
Charge Carrier Scattering ◽  
First Time

Abstract Precise angle-resolved magnetoresistance (ARMR) and magnetization measurements have revealed (i) strong charge transport and magnetic anisotropy and (ii) emergence of a huge number of magnetic phases in the ground state of isotopicaly 11B-enriched single crystals of TmB12 antiferromagnetic (AF) metal with fcc crystal structure and dynamic charge stripes. We analyze for the first time the angular H-φ phase diagrams of AF state of Tm11B12 reconstructed from experimental ARMR and magnetization data arguing that the symmetry lowering leads to the appearance of several radial phase boundaries between different phases in the AF state. It is proposed that the suppression of the indirect Ruderman–Kittel–Kasuya–Yosida (RKKY) exchange along 〈110〉 directions between nearest neighboring magnetic moments of Tm3+ ions and subsequent redistribution of conduction electrons to quantum fluctuations of the electron density (dynamic stripes) are the main factors responsible for the anisotropy. Essential (more than 25 % at T = 2 K) anisotropy of the Neel field in the (110) plane was found in Tm11B12 unlike to isotropic AF-P boundary in the H-φ phase diagrams of Ho11B12. Magnetoresistance components are discussed in terms of charge carrier scattering on the spin density wave, itinerant ferromagnetic nano-domains and on-site Tm3+ spin fluctuations.

scholarly journals Dielectric Function of a Quantum-Confined Thin Film with a Modified Pöschel–Teller Potential

2018 ◽  
Vol 63 (12) ◽  
pp. 1109 ◽  
Author(s):  
Kh. A. Gasanov ◽  
J. I. Guseinov ◽  
I. I. Abbasov ◽  
F. I. Mamedov ◽  
D. J. Askerov
Keyword(s):  
Dielectric Permittivity ◽  
Electron Gas ◽  
Two Dimensional ◽  
Quantum Nanostructures ◽  
Carrier Scattering ◽  
Scattering Potential ◽  
Quantum Confined ◽  
Charge Carrier Scattering ◽  
First Time ◽  
Analytical Expressions

The spatial and time dispersions of the dielectric permittivity of an electron gas in quasi-two-dimensional quantum nanostructures are studied. The screening of the charge-carrier scattering potential in a quantum-confined film with a modified P¨oschel–Teller potential is considered for the first time. Analytical expressions for the dielectric permittivity are obtained.

scholarly journals Spindigtheidsgolfgedrag van Cr-Si- en Cr-Ga-allooi-enkelkristalle

2000 ◽  
Vol 19 (1) ◽  
pp. 21-22
Author(s):  
A. R. E. Prinsloo
Keyword(s):  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Phase Diagrams ◽  
Single Crystals ◽  
Spin Density ◽  
Ultrasonic Wave ◽  
Magnetic Phase ◽  
Density Wave ◽  
Spin Density Wave ◽  
Velocity Measurements

The spin-density-wave (SDW) effects in Cr-Si and Cr-Ga alloy single crystals were investigated by means of thermal expansion, electrical resistivity and ultrasonic wave velocity measurements. The complete temperature-concentration and temperature-pressure magnetic phase diagrams of Cr-Ga were constructed.

Electronic Structure, Magnetism and Spin-Fluctuations in Fe-As Based Superconductors

2008 ◽  
Vol 1148 ◽  
Author(s):  
David Joseph Singh ◽  
Mao-Hua Du ◽  
Lijun Zhang ◽  
Alaska Subedi ◽  
Jiming An
Keyword(s):  
Electronic Structure ◽  
Fermi Surface ◽  
Density Functional ◽  
Density Wave ◽  
Spin Density Wave ◽  
Functional Results ◽  
Spin Fluctuations ◽  
Square Lattice ◽  
Itinerant Magnetism ◽  
Strong Spin

AbstractThe physical properties of the layered iron superconductors and related phases are discussed starting from first principles calculations. The electronic structure is described as that of metallic Fe2+ square lattice sheets with substantial direct Fe-Fe hopping and interactions with the neighboring anionic pnictogens or chalcogens. The materials have a semi-metallic band structure, and in particular the Fermi surface consists of small cylindrical electron sections centered at the zone corner, and compensating hole sections at the zone boundary. The density of states N(EF) is high placing the materials near itinerant magnetism in general, and furthermore the small Fermi surface sections are well nested leading to a tendency towards a spin density wave. Comparison of experimental and density functional results imply the presence of exceptionally strong spin fluctuations in these materials. Superconductivity is discussed within this context.

ON THE POSSIBILITY OF THE TEMPERATURE-INDUCED FERROMAGNETISM IN TiBe2 AND OTHER ITINERANT MAGNETS

1991 ◽  
Vol 05 (10) ◽  
pp. 721-724 ◽  
Author(s):  
DAVID M. IOSHPE
Keyword(s):  
Spin Density ◽  
Critical Field ◽  
Density Wave ◽  
Spin Density Wave ◽  
Wave Theory ◽  
Experimental Results ◽  
Spin Fluctuations ◽  
Density Wave Theory

We proposed earlier possible temperature-induced ferromagnetism (TIF) in TiBe 2, TiBe 2−x Cu x and other itinerant magnets. The value of the critical field H cr for the existence of TIF in TiBe 2, evaluated on the basis of our and others’ experimental results, coincide with the value H cr ≅610 G predicted by Enz within the spin density wave theory of itinerant antiferromagnetism (AFM). The possibilities of the existence in TiBe 2 of the TIF mechanism of spin fluctuations around the AFM mode as predicted by Moriya, and of the temperature-induced noncompensated itinerant AFM, i.e., ferromagnetism, are considered.

scholarly journals Collinear spin density wave order and anisotropic spin fluctuations in the frustrated J1−J2 chain magnet NaCuMoO4(OH)

2017 ◽  
Vol 96 (17) ◽  
Author(s):  
Kazuhiro Nawa ◽  
Makoto Yoshida ◽  
Masashi Takigawa ◽  
Yoshihiko Okamoto ◽  
Zenji Hiroi
Keyword(s):  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Spin Fluctuations

scholarly journals Magnetic-field-controlled spin fluctuations and quantum critically in Sr3Ru2O7

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
C. Lester ◽  
S. Ramos ◽  
R. S. Perry ◽  
T. P. Croft ◽  
M. Laver ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Capacity ◽  
Inelastic Neutron Scattering ◽  
Density Wave ◽  
Quantum Critical Point ◽  
Spin Density Wave ◽  
Continuous Phase ◽  
Spin Fluctuations ◽  
Electronic Heat Capacity ◽  
Electronic Heat

AbstractWhen the transition temperature of a continuous phase transition is tuned to absolute zero, new ordered phases and physical behaviour emerge in the vicinity of the resulting quantum critical point. Sr3Ru2O7 can be tuned through quantum criticality with magnetic field at low temperature. Near its critical field Bc it displays the hallmark T-linear resistivity and a $$T\,{{{{{{\mathrm{log}}}}}}}\,(1/T)$$ T log ( 1 / T ) electronic heat capacity behaviour of strange metals. However, these behaviours have not been related to any critical fluctuations. Here we use inelastic neutron scattering to reveal the presence of collective spin fluctuations whose relaxation time and strength show a nearly singular variation with magnetic field as Bc is approached. The large increase in the electronic heat capacity and entropy near Bc can be understood quantitatively in terms of the scattering of conduction electrons by these spin-fluctuations. On entering the spin-density-wave ordered phase present near Bc, the fluctuations become stronger suggesting that the order is stabilised through an “order-by-disorder” mechanism.

ELECTRONIC SPIN STATES IN CHROMIUM

1993 ◽  
Vol 07 (01n03) ◽  
pp. 634-637 ◽  
Author(s):  
A.B. KAISER ◽  
A.M. OLEŚ
Keyword(s):  
Spin Density ◽  
Density Wave ◽  
Spin Density Wave ◽  
Spin Fluctuations ◽  
Spatial And Temporal Variation ◽  
Electronic Spin ◽  
Static Spin ◽  
Different Types ◽  
Atomic Exchange ◽  
Atomic Centre

The electronic spin density and its spatial and temporal variation in Cr and its alloys are still not fully understood. The suggestion that Cr is an example of a spin-split metal is not supported by the evidence. Instead, it appears that three rather different types of magnetic moment are required to describe the electronic spin density in Cr: (1) static spin-density-wave moments and associated low-energy spin fluctuations that collapse at high temperatures; (2) higher-energy paramagnetic fluctuations that increase with temperature; and (3) 3d atomic moments formed due to intra-atomic exchange within 1 Å of the atomic centre showing almost no temperature dependence. We suggest further experiments to clarify this picture.

SPIN FLUCTUATION THEORY FOR TEMPERATURE-INDUCED FERROMAGNETISM IN ITINERANT ANTIFERROMAGNETS AND PARAMAGNETS

1995 ◽  
Vol 09 (10) ◽  
pp. 1171-1184 ◽  
Author(s):  
A.A. POVZNER ◽  
D.V. LIKHACHEV
Keyword(s):  
Order Parameter ◽  
Magnetic Phase ◽  
Spin Fluctuation ◽  
Density Wave ◽  
Spin Density Wave ◽  
Spin Fluctuations ◽  
Fluctuation Theory ◽  
Itinerant Electron ◽  
Electron Systems ◽  
Antiferromagnetic Transition

The possible occurrence of “temperature-induced ferromagnetism” in itinerant antiferromagnets with spin-density wave and strong paramagnets is discussed on the basis of spin fluctuation theory taking account of the effect of large ferromagnetic spin fluctuations. It is shown that the presence of a point of inflexion of the density of states near the Fermi level leads to the appearance of temperature-induced ferromagnetic order parameter in the itinerant electron systems. In addition the influence of this order parameter on the antiferromagnetic transition temperature is demonstrated and new mechanism of the magnetic phase transition is studied in relation to the magnetism of TiBe 2.

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