Antiferromagnetic ordering in 2‐1‐4 copper oxides

1988 ◽  
Vol 64 (10) ◽  
pp. 5950-5952 ◽  
Author(s):  
H. Tang ◽  
Y‐W. Du ◽  
Z‐Q. Qiu ◽  
J. C. Walker ◽  
J. S. Morgan ◽  
...  
Keyword(s):  
Copper Oxides ◽  
Antiferromagnetic Ordering

Crystal chemistry of high-Tc superconductors

1990 ◽  
Vol 48 (4) ◽  
pp. 1118-1119
Author(s):  
Maryvonne Hervieu
Keyword(s):  
Oxygen Deficiency ◽  
Large Family ◽  
Copper Oxides ◽  
High Tc Superconductors ◽  
High Tc ◽  
Single Mechanism ◽  
Square Planar ◽  
History Of ◽  
Bismuth Cuprates ◽  
New Compounds

Four years after the discovery of superconductivity at high temperature in the Ba-La-Cu-O system, more than thirty new compounds have been synthesized, which can be classified in six series of copper oxides: La2CuO4 - type oxides, bismuth cuprates, YBa2Cu3O7 family, thallium cuprates, lead cuprates and Nd2CuO4 - type oxides. Despite their quite different specific natures, close relationships allow their structures to be simply described through a single mechanism. The fifth first families can indeed be described as intergrowths of multiple oxygen deficient perovskite slabs with multiple rock salt-type slabs, according to the representation [ACuO3-x]m [AO]n.The n and m values are integer in the parent structures, n varying from 0 to 3 and m from 1 to 4; every member of this large family can thus be symbolized by [m,n]. The oxygen deficient character of the perovskite slabs involves the existence or the co-existence of several types of copper environment: octahedral, pyramidal and square planar.Both mechanisms, oxygen deficiency and intergrowth, are well known to give rise easily to nonstoichiometry phenomena. Numerous and various phenomena have actually been characterized in these cuprates, strongly depending on the thermal history of the samples.

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

Agglomeration and leaching behaviors of copper oxides with different chemical binders

2021 ◽  
Vol 28 (7) ◽  
pp. 1127-1134
Author(s):  
Sheng-hua Yin ◽  
Lei-ming Wang ◽  
Xun Chen ◽  
Ai-xiang Wu
Keyword(s):  
Copper Oxides

The surface restructuring of copper oxides with mixed oxidation-states and their efficient CO oxidation properties

2021 ◽  
Vol 289 ◽  
pp. 129378
Author(s):  
Wei Liu ◽  
Baoqin Wang ◽  
Chenchen Cui ◽  
Yiwen Zhang ◽  
Lixuan Wang ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Copper Oxides ◽  
Oxidation States ◽  
Surface Restructuring ◽  
Mixed Oxidation ◽  
Oxidation Properties

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 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

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
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