Static Magnetization Studies on the Family of Compounds Cd1−xFexCr2S4

1971 ◽  
Vol 49 (21) ◽  
pp. 2659-2670 ◽  
Author(s):  
M. R. Spender ◽  
A. H. Morrish
Keyword(s):  
Magnetic Properties ◽  
Simple Model ◽  
Iron Content ◽  
Low Temperatures ◽  
Magnetic Moments ◽  
Lattice Parameter ◽  
Static Magnetization ◽  
Magnetization Measurements ◽  
Steady Decrease ◽  
The Family

Static magnetization measurements have been made on a number of compounds in the family Cd1−xFexCr2S4 for [Formula: see text]. The magnetic moments at 0 °K fall with increasing iron content. The ordering temperatures rise and the Curie–Weiss parameters fall with increasing iron content. There is a steady decrease in lattice parameter with increasing x. A simple model is proposed in which the extra antiparallel electron on the Fe2+ ion is delocalized. The band in which the electrons move is assumed to have a trap for electrons in the vicinity of the A sites. The trap allows ionic behavior at low temperatures while at higher temperatures the electrons are itinerant. The model allows a consistent understanding of the magnetic properties.

scholarly journals Lattice Parameters, Electronic, and Magnetic Properties of Cubic Perovskite Oxides ARuO3 (A=Sr, Rb): A First‑Principles Study

2021 ◽  
Vol 31 (6) ◽  
pp. 335-340
Author(s):  
Ahmed Memdouh Younsi ◽  
Lakhdar Gacem ◽  
Mohamed Toufik Soltani
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
Electronic And Magnetic Properties ◽  
Symmetry Classes ◽  
The Family ◽  
Ferromagnetic Ground State ◽  
Parameter Values

Trioxides of rubidium, strontium, and ruthenium belong to the family of alkali and alkaline earth ruthenates. SrRuO3 crystallizes in various symmetry classes—orthorhombic, tetragonal, or cubic—whereas RbRuO3 is perovskite (cubic) structured and crystallizes only in the cubic space group Pm3¯¯¯m(No. 221). In this study, we investigated the structural stability as well as the electronic and magnetic properties of two cubic perovskites SrRuO3 and RbRuO3. We established the corresponding lattice parameters, magnetic moments, density of states (DOS), and band structures using ab‑initio density‑functional theory (DFT). Both compounds exhibited a metallic ferromagnetic ground state with lattice parameter values between 3.83 and 3.96 Å; RbRuO3 had magnetic moments between 0.29 and 0.34 µBwhereas SrRuO3 had magnetic moments between 1.33 and 1.66 µB. This study paves way for further RbRuO3 research.

Molten Gallium as a Non-Reactive Solvent: Synthesis of the Silicides RE2Ni3+xSi5-x (RE = Sm, Gd and Tb)

2003 ◽  
Vol 58 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Marina A. Zhuravleva ◽  
Mercouri G. Kanatzidis
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moments ◽  
Structure Type ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Cell Parameters ◽  
Antiferromagnetic Ordering ◽  
Effective Moment ◽  
The Family

The use of molten Ga as a non-reactive solvent for the synthesis of intermetallic silicides was demonstrated on the family RE2Ni3+xSi5-x (RE = Sm, Gd and Tb). The structure of Sm2Ni3+xSi5-x was solved from single crystal X-ray data in the orthorhombic space group Ibam, Z = 4, cell parameters a = 9.6396(12); b = 11.3219(14); and c = 5.6967(13) Å . The refinement based on the full-matrix least-squares on F2o [I > 2σ(I)] converged to final residuals R1/wR2 = 0.0206/0.0492. The structure of RE2Ni3+xSi5-x is related to the U2Co3Si5 structure type; however, discrepancies exist between the solution obtained for RE2Ni3+xSi5-x and that reported for U2Co3Si5. The magnetic properties studied on Tb2Ni3+xSi5-x indicate an antiferromagnetic ordering of magnetic moments centered at Tb ions at 13 K, and Curie-Weiss behavior at high temperatures with the effective moment close to that of free Tb3+ ion.

scholarly journals Contribution of on-site Coulomb repulsion energy to structural, electronic and magnetic properties of SrCoO3 for different space groups: first-principles study

2018 ◽  
Vol 35 (4) ◽  
pp. 846-856 ◽  
Author(s):  
Shibghatullah Muhammady ◽  
Inge M. Sutjahja
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moments ◽  
Coulomb Repulsion ◽  
Lattice Parameter ◽  
Experimental Result ◽  
Generalized Gradient ◽  
Teller Distortion ◽  
Space Group ◽  
Space Groups ◽  
Electronic And Magnetic Properties

Abstract We report structural, electronic, and magnetic properties of SrCoO3 in Pm3̅m and P4/mbm space groups, which are calculated by using generalized gradient approximation corrected with on-site Coulomb repulsion U and exchange energies J. The cubic lattice parameter a and local magnetic moments of Co (μCo) are optimized by varying U at Co 3d site. Employing ultrasoft pseudopotential, the values of U = 8 eV and J = 0.75 eV are the best choice for Pm3̅m space group. We found the value of μCo = 2.56 μB, which is consistent with the previous results. It was also found that Co 3d, hybridized with O 2p, is the main contributor to ferromagnetic metallic properties. Besides, norm-conserving pseudopotential promotes a, which is in good agreement with experimental result. However, it is not suitable for P4/mbm space group. By using ultrasoft pseudopotential, the value of U = 3 eV (J = 0.75) is the most suitable for P4/mbm group. Ferromagnetic metallic properties, Jahn-Teller distortion, and reasonable lattice parameters have been obtained. This study shows that U has significant contribution to the calculated properties and also points out that P4/mbm space group with US-PP is suitable to describe experimental results.

scholarly journals Исследование структуры и магнитных свойств сплавов Fe-=SUB=-8-=/SUB=-Rh-=SUB=-8-x-=/SUB=-Z-=SUB=-x-=/SUB=- (Z=Mn, Pt, Co; x=1, 2 и 3) первопринципными методами

2018 ◽  
Vol 60 (6) ◽  
pp. 1122
Author(s):  
О.О. Павлухина ◽  
В.В. Соколовский ◽  
В.Д. Бучельников ◽  
М.А. Загребин
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Magnetic Moments ◽  
Magnetic Ordering ◽  
Lattice Parameter ◽  
Lattice Parameters ◽  
The Third ◽  
Equilibrium Lattice Parameter

AbstractThe results of first-principles studies of the structure and magnetic properties of Fe–Rh–Z alloys conducted using the VASP package are reported. The magnetic moments and lattice parameters are determined, and the possibility of existence of stable tetragonal distortions in Fe–Rh–Z alloys with various magnetic configurations set by the level of doping with Mn, Pt, and Co is examined. It is demonstrated that the equilibrium lattice parameter and the type of magnetic ordering change with the concentration of the third element.

scholarly journals Electronic and Magnetic Properties of Half Metallic Heusler Alloy Co2MnSi: A First-Principles Study

2017 ◽  
Vol 4 (1) ◽  
pp. 60
Author(s):  
Prakash Sharma ◽  
Gopi Chandra Kaphle
Keyword(s):  
Magnetic Properties ◽  
Band Structure ◽  
Heusler Alloy ◽  
Density Functional ◽  
Magnetic Moments ◽  
Heusler Alloys ◽  
Tight Binding ◽  
Lattice Parameter ◽  
Half Metallic ◽  
Electronic And Magnetic Properties

<p class="Default">Heusler alloys have been of great interest because of their application in the field of modern technological applications. Electronic and magnetic properties of Co, Mn, Si and the Heusler alloy Co<sub>2</sub>MnSi have been studied using Density functional theory based Tight Binding Linear Muffin Tin Orbital with Atomic Sphere Approximation (TB-LMTO-ASA) approach. From the calculation lattice parameter of optimized structure of Co, Mn, Si and Co<sub>2</sub>MnSi are found to be 2.52Å, 3.49Å, 5.50Å, 5.53Å respectively. Band structure calculations show that Co and Mn are metallic, Si as semi-conducting while the Heusler alloy Co<sub>2</sub>MnSi as half-metallic in nature with band gap 0.29eV. The charge density plot indicates major bonds in Co<sub>2</sub>MnSi are ionic in nature. Magnetic property has been studied using the density of states (DOS), indicating that Co and Co2MnSi are magnetic with magnetic moments 2.85μ<sub>B</sub> and 4.91μ<sub>B</sub> respectively. The contribution of orbital in band structure, DOS and magnetic moments are due to d-orbital of Co and Mn and little from s and p-orbital of Si in Co<sub>2</sub>MnSi alloy.</p><p><strong>Journal of Nepal Physical Society</strong><em><br /></em>Volume 4, Issue 1, February 2017, Page: 60-66</p>

scholarly journals A Quantum–Mechanical Study of Clean and Cr–Segregated Antiphase Boundaries in Fe3Al

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3954 ◽  
Author(s):  
Martin Friák ◽  
Monika Všianská ◽  
Mojmír Šob
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moments ◽  
Lattice Parameter ◽  
Quantum Mechanical ◽  
Strong Impact ◽  
Antiphase Boundaries ◽  
Cubic Symmetry ◽  
Mechanical Study ◽  
Quantum Mechanical Study ◽  
The Impact

We present a quantum-mechanical study of thermodynamic, structural, elastic, and magnetic properties of selected antiphase boundaries (APBs) in Fe 3 Al with the D0 3 crystal structure with and without Cr atoms. The computed APBs are sharp (not thermal), and they have {001} crystallographic orientation. They are characterized by a mutual shift of grains by 1/2⟨100⟩a where a is the lattice parameter of a cube-shaped 16-atom elementary cell of Fe 3 Al, i.e., they affect the next nearest neighbors (APB-NNN type, also called APB-D0 3 ). Regarding clean APBs in Fe 3 Al, the studied ones have only a very minor impact on the structural and magnetic properties, including local magnetic moments, and the APB energy is rather low, about 80 ± 25 mJ/m 2 . Interestingly, they have a rather strong impact on the anisotropic (tensorial) elastic properties with the APB-induced change from a cubic symmetry to a tetragonal one, which is sensitively reflected by the directional dependence of linear compressibility. The Cr atoms have a strong impact on magnetic properties and a complex influence on the energetics of APBs. In particular, the Cr atoms in Fe 3 Al exhibit clustering tendencies even in the presence of APBs and cause a transition from a ferromagnetic (Cr-free Fe 3 Al) into a ferrimagnetic state. The Fe atoms with Cr atoms in their first coordination shell have their local atomic magnetic moments reduced. This reduction is synergically enhanced (to the point when Fe atoms are turned non-magnetic) when the influence of clustering of Cr atoms is combined with APBs, which offer specific atomic environments not existing in the APB-free bulk Fe 3 Al. The impact of Cr atoms on APB energies in Fe 3 Al is found to be ambiguous, including reduction, having a negligible influence or increasing APB energies depending on the local atomic configuration of Cr atoms, as well as their concentration.

Electronic and magnetic properties of BaUO3 by modified Becke–Johnson (mBJ) functional

2018 ◽  
Vol 32 (15) ◽  
pp. 1850164
Author(s):  
Ghulam Mustafa ◽  
Najm ul Aarifeen ◽  
Ahmad Afaq ◽  
Muhammad Asif
Keyword(s):  
Magnetic Properties ◽  
Density Of States ◽  
High Performance ◽  
Structural Parameters ◽  
Ambient Pressure ◽  
Magnetic Moments ◽  
Ferromagnetic Material ◽  
Lattice Parameter ◽  
Full Potential ◽  
Electronic And Magnetic Properties

First-principle calculations have been performed to study the structural, electronic and magnetic properties of BaUO3 in cubic perovskite. The lattice parameter, bulk modulus, bond length, band structures, density of states, and magnetic moments are evaluated using Full Potential Linearized Augmented Plane Wave (FP-LAPW) method in Wien2k-code with GGA as exchange and correlation functional and mBJ functional is used to improve the results along with GGA+U to review magnetic properties. It is found that our calculated structural parameters are in good agreement with experimental results and other work at ambient pressure. The density of states results for spin up and spin down channels show that BaUO3 is an half ferromagnetic material, so we may use this material to make high-performance spintronics devices.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

ON THE PROCESSING OF HEMATITE RAW MATERIALS AT THE KRYVOROZHSK MINING AND PROCESSING PLANT OF OXIDIZED ORE ON TECHNOLOGY OF DIRECT RECOVERY ITmk3

2018 ◽  
pp. 32-37
Author(s):  
P.I. Loboda ◽  
Younes Razaz ◽  
S. Grishchenko
Keyword(s):  
Magnetic Properties ◽  
Cast Iron ◽  
Iron Content ◽  
Raw Materials ◽  
Direct Reduction ◽  
Processing Plant ◽  
High Iron Content ◽  
High Iron ◽  
Direct Restoration ◽  
First Time

Purpose. To substantiate the efficiency of processing hematite raw materials at the Krivoy Rog Mining and Processing Plant of Oxidized Ores using the direct reduction technology itmk3®. Metodology. Analysis of the results of the itmk3® direct restoration technology developed by Kobe Steel Ltd., Japan and Hares Engineering GmbX, Austria, with a view to using it to process Krivbass hematite ores into granulated iron (so-called “nuggets”). Findings. The involvement in the production of hematite ores (oxidized quartzite) of Krivbass with high iron content, but with low magnetic properties for their processing into granular cast iron is grounded. Originality. The use of itmk3® direct reduction technology from Kobe Steel Ltd., Japan and Hares Engineering GmbH, Austria for the processing of Krivbass hematite ores into granular cast iron is justified for the first time. Practical value. The efficiency of the use of hematite ores (oxidized quartzite) has been substantiated, which can significantly reduce the costs in the mining cycle for the economical production of metallurgical products.

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