scholarly journals Martensitic transition assisted modification of the antiferromagnetic ordering in Ge-site doped MnNiGe alloys

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
S. C. Das ◽  
J. Sannigrahi ◽  
P. Dutta ◽  
S. Pramanick ◽  
D. Khalyavin ◽  
...  
Keyword(s):  
Martensitic Transition ◽  
Antiferromagnetic Ordering

Photoluminescence and Magnetic Properties of Undoped and (Mn, Co) co-doped ZnO Nanoparticles

2020 ◽  
Vol 16 (4) ◽  
pp. 655-666
Author(s):  
Mona Rekaby
Keyword(s):  
Magnetic Properties ◽  
Zno Nanoparticles ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Structural Defects ◽  
Ferromagnetic Behavior ◽  
Secondary Phases ◽  
Antiferromagnetic Ordering ◽  
Doped Zno ◽  
Co Doped

Objective: The influence of Manganese (Mn2+) and Cobalt (Co2+) ions doping on the optical and magnetic properties of ZnO nanoparticles was studied. Methods: Nanoparticle samples of type ZnO, Zn0.97Mn0.03O, Zn0.96Mn0.03Co0.01O, Zn0.95Mn0.03 Co0.02O, Zn0.93Mn0.03Co0.04O, and Zn0.91Mn0.03Co0.06O were synthesized using the wet chemical coprecipitation method. Results: X-ray powder diffraction (XRD) patterns revealed that the prepared samples exhibited a single phase of hexagonal wurtzite structure without any existence of secondary phases. Transmission electron microscope (TEM) images clarified that Co doping at high concentrations has the ability to alter the morphologies of the samples from spherical shaped nanoparticles (NPS) to nanorods (NRs) shaped particles. The different vibrational modes of the prepared samples were analyzed through Fourier transform infrared (FTIR) measurements. The optical characteristics and structural defects of the samples were studied through Photoluminescence (PL) spectroscopy. PL results clarified that Mn2+ and Co2+ doping quenched the recombination of electron-hole pairs and enhanced the number of point defects relative to the undoped ZnO sample. Magnetic measurements were carried out at room temperature using a vibrating sample magnetometer (VSM). (Mn, Co) co-doped ZnO samples exhibited a ferromagnetic behavior coupled with paramagnetic and weak diamagnetic contributions. Conclusion: Mn2+ and Co2+ doping enhanced the room temperature Ferromagnetic (RTFM) behavior of ZnO. In addition, the signature for antiferromagnetic ordering between the Co ions was revealed. Moreover, a strong correlation between the magnetic and optical behavior of the (Mn, Co) co-doped ZnO was analyzed.

Antiferromagnetic ordering in GdCo[sub 0.17]Sn[sub 2] and GdCu[sub 0.17]Sn[sub 2]

2013 ◽  
Author(s):  
Krishanu Ghosh ◽  
Chandan Mazumdar ◽  
R. Ranganathan ◽  
S. Mukherjee
Keyword(s):  
Antiferromagnetic Ordering

scholarly journals Preparation of iron(IV) nitridoferrate Ca4FeN4 through azide-mediated oxidation under high-pressure conditions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Simon D. Kloß ◽  
Arthur Haffner ◽  
Pascal Manuel ◽  
Masato Goto ◽  
Yuichi Shimakawa ◽  
...  
Keyword(s):  
High Pressure ◽  
Transition Metal Nitrides ◽  
Oxidative Potential ◽  
Antiferromagnetic Ordering ◽  
Chemical Inertness ◽  
High Thermodynamic Stability ◽  
Li Ion ◽  
Pressure Synthesis ◽  
Ternary Nitride ◽  
Mediated Oxidation

AbstractTransition metal nitrides are an important class of materials with applications as abrasives, semiconductors, superconductors, Li-ion conductors, and thermoelectrics. However, high oxidation states are difficult to attain as the oxidative potential of dinitrogen is limited by its high thermodynamic stability and chemical inertness. Here we present a versatile synthesis route using azide-mediated oxidation under pressure that is used to prepare the highly oxidised ternary nitride Ca4FeN4 containing Fe4+ ions. This nitridometallate features trigonal-planar [FeN3]5− anions with low-spin Fe4+ and antiferromagnetic ordering below a Neel temperature of 25 K, which are characterised by neutron diffraction, 57Fe-Mössbauer and magnetisation measurements. Azide-mediated high-pressure synthesis opens a way to the discovery of highly oxidised nitrides.

scholarly journals Crystal-to-Crystal Transformation from K2[Co(C2O4)2(H2O)2]·4H2O to K2[Co(μ-C2O4)(C2O4)]

2021 ◽  
Vol 7 (6) ◽  
pp. 77
Author(s):  
Bin Zhang ◽  
Yan Zhang ◽  
Guangcai Chang ◽  
Zheming Wang ◽  
Daoben Zhu
Keyword(s):  
Hydrogen Bond ◽  
Physical Properties ◽  
Crystal Structures ◽  
Molecular Crystal ◽  
Trigonal Prism ◽  
Space Group ◽  
Cell Parameters ◽  
Oxalate Anion ◽  
Crystal Transformation ◽  
Antiferromagnetic Ordering

Crystal-to-crystal transformation is a path to obtain crystals with different crystal structures and physical properties. K2[Co(C2O4)2(H2O)2]·4H2O (1) is obtained from K2C2O4·2H2O, CoCl2·6H2O in H2O with a yield of 60%. It is crystallized in the triclinic with space group P1 and cell parameters: a = 7.684(1) Å, b = 9.011(1) Å, c = 10.874(1) Å, α = 72.151(2)°, β = 70.278(2)°, γ = 80.430(2)°, V = 670.0(1) Å3, Z = 2 at 100 K. 1 is composed of K+, mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. Co2+ is coordinated by two bidentated oxalate anion and two H2O in an octahedron environment. There is a hydrogen bond between mononuclear anion [Co(C2O4)2(H2O)22−] and H2O. K2[Co(μ-C2O4)(C2O4)] (2) is obtained from 1 by dehydration. The cell parameters of 2 are a = 8.460(5) Å, b = 6.906 (4) Å, c = 14.657(8) Å, β = 93.11(1)°, V = 855.0(8) Å3 at 100 K, with space group in P2/c. It is composed of K+ and zigzag [Co(μ-C2O4)(C2O42−]n chain. Co2+ is coordinated by two bisbendentate oxalate and one bidentated oxalate anion in trigonal-prism. 1 is an antiferromagnetic molecular crystal. The antiferromagnetic ordering at 8.2 K is observed in 2.

scholarly journals Synthesis and Properties of Monolayer MnSe with Unusual Atomic Structure and Antiferromagnetic Ordering

ACS Nano ◽  
2021 ◽  
Author(s):  
Markus Aapro ◽  
Md. Nurul Huda ◽  
Jeyakumar Karthikeyan ◽  
Shawulienu Kezilebieke ◽  
Somesh C. Ganguli ◽  
...  
Keyword(s):  
Atomic Structure ◽  
Antiferromagnetic Ordering

Crystallographic Features of Electronic States in the Highly-Correlated Electronic System Sr1-xSmxMnO3 around x = 0.50

2016 ◽  
Vol 879 ◽  
pp. 2158-2163 ◽  
Author(s):  
Misato Yamagata ◽  
Yasuhide Inoue ◽  
Yasumasa Koyama
Keyword(s):  
Electronic States ◽  
Electronic System ◽  
Electron System ◽  
Correlated Electron ◽  
Antiferromagnetic Ordering ◽  
Incommensurate Modulation ◽  
Charge Modulations ◽  
Highly Correlated ◽  
Correlated Electron System ◽  
Coexistence State

The highly-correlated electron system Sr1-xSmxMnO3 (SSMO) with the simple-perovskite structure has been found to exhibit fascinating electronic states accompanying antiferromagnetic and ferromagnetic orderings. It was, in particular, reported that the electronic state for 0.46 ≤ x ≤ 0.54 was characterized by the coexistence state consisting of the A-type antiferromagnetic and ferromagnetic states. However, the features of the coexistence state in this Sm-content range have not been understood yet. We have thus investigated the crystallographic features of prepared SSMO samples with 0.46 ≤ x ≤ 0.55, mainly by transmission electron microscopy. As a result, all prepared SSMO samples were first confirmed to have the orthorhombic-Pnma structure at 300 K. When the temperature was lowered from 300 K, in the case of x=0.47, the disordered-Pnma state was found to be transformed into an orbital-modulated (OM) state accompanying an incommensurate modulation. The notable feature of the OM state is that the state becomes unstable with increasing Sm contents at 100 K. In other words, the OM state was never changed into the CE-type state with the orbital and charge modulations. In addition, no orbital-ordered state for the A-type antiferromagnetic ordering was also found for 0.46 ≤ x ≤ 0.55.

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