Exchange coupling across the cyanide bridge: structural and DFT interpretation of the magnetic properties of a binuclear chromium(iii) complex

2006 ◽  
pp. 948-954 ◽  
Author(s):  
Pablo Alborés ◽  
Leonardo D. Slep ◽  
Thomas Weyhermüller ◽  
Eva Rentschler ◽  
Luis M. Baraldo
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Cyanide Bridge

Rare earth permanent magnetic nanostructures: chemical design and microstructure control to optimize magnetic properties

2021 ◽  
Author(s):  
Junjie Xu ◽  
Kai Zhu ◽  
Song Gao ◽  
Yanglong Hou
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Exchange Coupling ◽  
Magnetic Nanostructures ◽  
Microstructure Control ◽  
Size And Shape ◽  
Chemical Design

The routes for the optimization of the magnetic properties of rare earth permanent magnetic nanostructures are discussed, i.e. the control of microstructure, such as size and shape as well as the exchange-coupling interactions.

A Study on The Phase Transformation and Exchange-Coupling of (Nd0 95La0 05)9 5FebalCo5Nb2B10.5 Nanocomposites

1999 ◽  
Vol 577 ◽  
Author(s):  
Q. Chen ◽  
B. M. Ma ◽  
B. Lu ◽  
M. Q. Huang ◽  
D. E. Laughlin
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Phase Transformation ◽  
Thermal Treatment ◽  
Grain Growth ◽  
Exchange Coupling ◽  
Phase Distribution ◽  
Maximum Energy ◽  
Treatment Temperature ◽  
Phase Identification

ABSTRACTThe phase transformation and the exchange coupling in (Ndo095Lao005)9.5FebaICOsNb 2BI05 have been investigated. Nanocomposites were obtained by treating amorphous precursors at temperatures ranging from 650TC to 9500C for 10 minutes. The magnetic properties were characterized via the vibrating sample magnetometer (VSM). X-ray diffraction (XRD), thermomagnetic analysis (TMA), and transmission electron microscopy (TEM) were used to perform phase identification, measure grain size, and analyze phase distribution. The strength of the exchange coupling between the magnetically hard and soft phases in the corresponding nanocomposite was analyzed via the AM-versus-H plot. It was found that the remanence (Br), coercivity (Hci), and maximum energy product (BHmax) obtained were affected by the magnetic phases present as well as the grain size of constituent phases and their distribution. The optimal magnetic performance, BHm, occurred between 700°C to 750°C, where the crystallization has completed without excessive grain growth. TMA and TEM indicated that the system was composed of three phases at this point, Nd2(Fe Co) 14B, ca-Fe, and Fe3B. The exchange coupling interaction among these phases was consistently described via the AM-versus-H plot up to 750°C. The Br, Hci, and BHmax degraded severely when the thermal treatment temperature increased from 750°C. This degradation may be attributed to the grain growth of the main phases, from 45 to 68nm, and the development of precipitates, which grew from 5nm at 750°C to 12nm at 850°C. Moreover, the amount of the precipitates was found to increase with the thermal treatment temperatures. The precipitates, presumably borides, may cause a decrease in the amount of the a-Fe and Fe 3B and result in a redistribution of the Co in the nanocomposites. The increase of the Co content in the Nd 2(Fe Co) 14B may explain the increase of its Curie temperature with the thermal treatment temperatures. In this paper, we examine the impacts of these factors on the magnetic properties of (Ndo 95Lao 05)9 5FebaICosNb2B10.5 nanocomposite.

scholarly journals Design of Pure Heterodinuclear Lanthanoid Cryptate Complexes

2021 ◽  
Author(s):  
Christian Dirk Buch ◽  
Steen Hansen ◽  
Dmitri Mitcov ◽  
Camilla Mia Tram ◽  
Gary Nichol ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Magnetic Properties ◽  
13C Nmr ◽  
Exchange Coupling ◽  
Lanthanide Ions ◽  
Squid Magnetometry ◽  
Counter Ion ◽  
Synthetic Procedure ◽  
Optical And Magnetic Properties ◽  
Fine Tune

Heterolanthanide complexes are difficult to synthesize owing to the similar chemistry of the lanthanide ions. Conse-quently, very few purely heterolanthanide complexes have been synthesized. This is despite the fact that such complexes hold inter-esting optical and magnetic properties. To fine-tune these properties, it is important that one can choose complexes with any given combination of lanthanides. Herein we report a synthetic procedure which yields pure heterodinuclear lanthanide cryptates LnLn*LX3 (X = NO3- or OTf-) based on the cryptand H3L = N[(CH2)2N=CH-R-CH=N-(CH2)2]3N (R = m-C6H2OH-2-Me-5). In the synthesis the choice of counter ion and solvent prove crucial in controlling the Ln-Ln*composition. Choosing the optimal solvent and counter ion affords pure heterodinuclear complexes with any given combination of Gd(III)-Lu(III) including Y(III). To demon-strate the versatility of the synthesis all dinuclear combinations of Y(III), Gd(III), Yb(III) and Lu(III) were synthesized resulting in 10 novel complexes of the form LnLn*L(OTf)3 with LnLn* = YbGd 1, YbY 2, YbLu 3, YbYb 4, LuGd 5, LuY 6, LuLu 7, YGd 8, YY 9 and GdGd 10. Through the use of 1H, 13C NMR and mass spectrometry the heterodinuclear nature of YbGd, YbY, YbLu, LuGd, LuY and YGd was confirmed. Crystal structures of LnLn*L(NO3)3 reveal short Ln-Ln distances of ~3.5 Å. Using SQUID magnetometry the exchange coupling between the lanthanide ions was found to be anti-ferromagnetic for GdGd and YbYb while ferromagnetic for YbGd.

Magnetooptical and magnetic properties of Fe/ZnTe/Fe nanoheterostructures: Manifestation of interlayer exchange coupling

2006 ◽  
Vol 102 (2) ◽  
pp. 149-156 ◽  
Author(s):  
I. D. Lobov ◽  
V. M. Maevskii ◽  
M. M. Kirillova ◽  
A. V. Korolev ◽  
F. A. Pudonin
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Interlayer Exchange Coupling ◽  
Interlayer Exchange

scholarly journals Magnetic properties, interlayer exchange coupling and electric transport in Fe/Cr/Fe trilayers

2002 ◽  
Vol 82 (1) ◽  
pp. 85-104 ◽  
Author(s):  
A. Vernes ◽  
P. Weinberger ◽  
C. Blaas ◽  
P. Mohn ◽  
L. Szunyogh ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Electric Transport ◽  
Interlayer Exchange Coupling ◽  
Interlayer Exchange

Unusual Magnetic Properties of Fe/Ni Bilayers on Cu(100)

2000 ◽  
Vol 648 ◽  
Author(s):  
B. Schirmer ◽  
X. Liu ◽  
M. Wuttig
Keyword(s):  
Magnetic Properties ◽  
Surface Layer ◽  
Molecular Beam Epitaxy ◽  
Exchange Coupling ◽  
Molecular Beam ◽  
Interface Layer ◽  
Temperature Dependent ◽  
Iron Films ◽  
Magnetic Phases ◽  
Rich Variety

AbstractUltrathin iron films grown on Cu(100) have been found to exhibit a rich variety of structural and magnetic phases. In the present work, Fe/Ni bilayers have been prepared by molecular beam epitaxy to explore novel magnetic phenomena introduced by the ferromagnetic (FM) Ni underlayer. Unusual properties have been observed by measuring the temperature dependent magnetic properties. For 5.3 ML Fe on 7 ML Ni, a temperature dependent exchange coupling in the Fe film has been observed between the FM surface layer and FM interface layer.

PHASE EVOLUTION AND MAGNETIC PROPERTIES OF TbCu7-TYPE (Sm, Pr)Co7-xHfxMy (x = 0-0.5; y = 0-0.14) RIBBONS

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1663-1669 ◽  
Author(s):  
H. W. Chang ◽  
S. T. Huang ◽  
I. W. Chen ◽  
C. W. Chang ◽  
W. C. Chang
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Exchange Coupling ◽  
Coupling Effect ◽  
Anisotropy Field ◽  
Phase Evolution ◽  
Phase Constitution ◽  
Melt Spun

The effects of Hf substitution and C content on the magnetic properties, phase evolution, and microstructure of melt spun ( Sm , Pr ) Co 7- x Hf x C y ( x = 0-0.5; y = 0-0.14) ribbons have been studied. A proper Hf substitution is helpful not only in stabilizing 1:7 phase but also in enhancing its magnetic anisotropy field. As a result, magnetic properties of B r = 6.4 kG , i H c = 7.3 kOe and ( BH ) max = 8.7 MGOe for SmCo 6.9 Hf 0.1 ribbons are obtained. Besides, a small amount of C addition in the ribbons could slightly modify phase constitution and effectively refine their microstructure to strengthen the exchange coupling effect between magnetic grains. Furthermore, a slight Pr substitution for Sm may further increase the magnetization and the magnetic properties of the ribbons. The optimal magnetic properties of B r = 7.1 kG , i H c = 8.5 kOe and ( BH ) max = 11.2 MGOe could be achieved for the directly quenched Sm 0.8 Pr 0.2 Co 6.9 Hf 0.1 C 0.12 ribbons.

Magnetic Properties Study of the Nano-Alloy Fe1+xCo1−x by Monte-Carlo Simulations

SPIN ◽  
2019 ◽  
Vol 09 (01) ◽  
pp. 1950002 ◽  
Author(s):  
I. El Housni ◽  
H. Labrim ◽  
N. El Mekkaoui ◽  
S. Idrissi ◽  
R. Khalladi ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Magnetic Properties ◽  
Monte Carlo Simulations ◽  
Phase Diagrams ◽  
Ground State ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Metropolis Algorithm ◽  
Spintronic Devices ◽  
Temperature Exchange

Motivated by spintronic devices and their applications, we engineer a model to investigate the magnetic properties of the magnetic nano-alloy Fe[Formula: see text]Co[Formula: see text]. Where [Formula: see text] is the fraction of iron atoms Fe substituted by the cobalt Co atoms, [Formula: see text] corresponds to 50% Fe atoms and 50% Co atoms, this compound is then called equiatomic FeCo. The purpose of this work is to apply the Monte-Carlo Simulations (MCS), under Metropolis algorithm to predict the magnetic properties of such system. In a first step, we propose a model describing this system including different exchange coupling interactions. Then, we establish and analyze the ground state phase diagrams, in different planes. For non-null temperature values, applied MCS under the Metropolis algorithm. The behavior of both the magnetizations and the susceptibilities are illustrated as a function of temperature. Also the effect of the different exchange coupling interactions is studied and discussed. The hysteresis loops are presented and analyzed for specific values of temperature, exchange coupling interactions and concentrations.

Determination of interface layer effects on magnetic properties of nanocomposite magnets and exchange coupling between magnetic entities

2019 ◽  
Vol 480 ◽  
pp. 454-462 ◽  
Author(s):  
Nadeem Abbas ◽  
Fang Wang ◽  
Hanyang Ren ◽  
J. Ping Liu ◽  
Weixing Xia ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Interface Layer ◽  
Nanocomposite Magnets

scholarly journals Enhanced magnetic properties in ZnCoAlO caused by exchange-coupling to Co nanoparticles

2016 ◽  
Vol 18 (11) ◽  
pp. 113040 ◽  
Author(s):  
Qi Feng ◽  
Wala Dizayee ◽  
Xiaoli Li ◽  
David S Score ◽  
James R Neal ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Exchange Coupling ◽  
Co Nanoparticles
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