Search results for "Magnetic moment"

First Cobalt(II) Spin Crossover Compound with N4S2-Donorset

2020

Herein we report the synthesis and characterization of a novel bis-tridentate 1,3,4-thiadiazole ligand (L = 2,5-bis[(2-pyridylmethyl)thio]methyl-1,3,4-thiadiazole). Two new mononuclear complexes of the type [MII(L)2](ClO4)2 (with M = FeII (C1) and CoII (C2)) have been synthesized, containing the new ligand (L). In both complexes the metal centers are coordinated by an N4S2-donorset and each of the two ligands is donating to the metal ion with just one of the tridentate pockets. The iron(II) complex (C1) is in the low spin [LS] state below room temperature and shows an increase in the magnetic moment only above 300 K. In contrast, the cobalt(II) complex (C2) shows a gradual spin crossover (S…

Surface Chemistry Controls Magnetism in Cobalt Nanoclusters

2016

Magnetic properties of Co13 and Co55 nanoclusters, passivated by surface ligand shells that exhibit varying electronic interactions with the metal, are studied using density functional theory. The calculations show that the chemical nature of the bond between the ligand and the metal core (X-type or L-type) impacts the total magnetic moment of Co nanoclusters dramatically. Furthermore, the chemical identity of the ligand within each binding motif then provides a fine handle on the exhibited magnetic moment of the cluster. Thus, ligand shell chemistry is predicted to not only stabilize Co nanoclusters, but provide a powerful approach to control their magnetic properties, which combined enabl…

Magnetic properties and61Ni Mössbauer spectroscopy of the ternary phosphide CrNiP

2008

The results of x-ray diffraction, dc magnetization, and 61Ni Mossbauer spectroscopy studies of the ternary phosphide CrNiP are reported. This compound crystallizes in the orthorhombic Co2P-type structure (space group Pnma) with the lattice parameters a = 5.7965(1) A, b = 3.5337(1) A, and c = 6.8123(2) A. NiCrP is a ferromagnet with Curie temperature TC = 135.1(1) K. The ferromagnetic-to-paramagnetic transition is characterized by the critical exponents β = 0.355(22), γ = 1.241(18), and δ = 4.585(20). Their values are close to those of a 3D Heisenberg ferromagnet. The temperature dependence of the magnetic susceptibility above TC follows the modified Curie–Weiss law with a paramagnetic Curie…

Interface magnetization of ultrathin epitaxial Co2FeSi(110)/Al2O3films

2007

Element-specific magnetic properties of ultrathin epitaxial Co2FeSi(110) films were measured using x-ray magnetic circular dichroism (XMCD). The epitaxial Heusler films were grown by RF magnetron sputtering on substrates. The magnetization of thicker films as determined by XMCD is smaller than expected for a half-metallic material. In addition, the magnetization decreases considerably for films thinner than 10 nm. The thickness dependence of the magnetic moment can be described by introducing a certain number of dead layers representing a deficiency of magnetization at the interfaces. Quantitative evaluation results in a dead layer thickness of 0.8 nm at room temperature, consisting of a te…

Magnetic properties of some rare‐earth magnesium compounds RMg2

1981

The magnetic properties of the compounds PrMg2, NdMg2, DyMg2, and ErMg2 were studied by means of neutron diffraction at various temperatures. All these compounds give rise to ferromagnetic ordering. The absolute values of the magnetic moments in the magnetically ordered state are lower than the free‐ion values. Inelastic neutron scattering at several temperatures was studied in PrMg2 and NdMg2. Analysis of the scattering data in conjunction with the results of specific‐heat and magnetization measurements shows that PrMg2 is an induced‐moment system (G3 ground state), where quadrupolar effects carry a large weight in determining the magnetic properties. The values found for the crystal‐field…

Nuclear Magnetic Moments ofBi205,207,209Isotopes—Hyperfine Structure of the 15-dayBi2053067-Å Line

1975

Martensite transition and microscopic magnetism of epitaxial Ni2MnGa films

2007

AbstractA magnetically induced shape memory effect in Ni2MnGa results in huge magnetostrictive effects of several percent. Using x-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) we investigated element specific magnetic moments and electronic structure of single crystalline, (110) oriented Ni2MnGa films on a-plane Al2O3 substrates in the austenite and martensite state. The structural phase transition of the samples is evident from temperature dependent x-ray diffraction and magnetization measurements. The Ni XAS differ significantly for temperatures above and below the martensite transition in agreement with published ab-initio calculations. Using XAS in transmissi…

Mn(IV) and Co(III)-complexes of –OH-rich ligands possessing O2N, O3N and O4N cores: syntheses, characterization and crystal structures

2003

Mn(IV) and Co(III) complexes of tridentate –OH–rich ligands possessing O2N, O3N and O4N donor sets were synthesized, characterized and their structures were established by single crystal X-ray diffraction, where the binding core is O4N2. In the structurally characterized complexes, the coordination geometry about the metal ion was found to be distorted octahedral.

Support work function as a descriptor and predictor for the charge and morphology of deposited Au nanoparticles.

2020

We show, using density functional theory calculations, that the charge, magnetic moment, and morphology of deposited Au nanoclusters can be tuned widely by doping the oxide support with aliovalent cations and anions. As model systems, we have considered Aun (n = 1, 2, or 20) deposited on doped MgO and MgO/Mo supports. The supports have been substitutionally doped with varying concentrations θ of F, Al, N, Na, or Li. At θ = 2.78%, by varying the dopant species, we are able to tune the charge of the Au monomer between −0.84e and +0.21e, the Au dimer between −0.87e and −0.16e, and, most interestingly, Au20 between −3.97e and +0.49e. These ranges can be further extended by varying θ. These chan…

Al driven peculiarities of local coordination and magnetic properties in single phase Alx CrFeCoNi high entropy alloys

2021

The authors thank the Helmholtz-Zentrum Berlin for the provision of access to synchrotron radiation facilities and allocation of synchrotron radiation at the PM2-VEKMAG, BAMline, and UE46_PGM-1 beamlines of BESSY II at HZB as well as measurement time for magnetometry at HZB CoreLab for Quantum Materials. A. S. acknowledges personal funding from CALIPSOplus project (the Grant Agreement no. 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020). The financial support for the VEKMAG project and the PM2-VEKMAG beamline by the German Federal Ministry for Education and Research (Nos. BMBF 05K10PC2, 05K10WR1, 05K10KE1) and by HZB is cordially acknowledged by all co-author…