Hyperfine Fields in Ultrathin Fe and FeAu Alloy Films on Au (111)

1993 ◽  
Vol 313 ◽  
Author(s):  
M. Brockmann ◽  
L. Pfau ◽  
G. Lugert ◽  
G. Bayreuther
Keyword(s):  
Magnetic Properties ◽  
Magnetic Moments ◽  
Anisotropy Field ◽  
Iron Film ◽  
Squid Magnetometry ◽  
Hyperfine Fields ◽  
Iron Films ◽  
Alloy Films ◽  
Alloy Zone ◽  
Sharp Interfaces

ABSTRACTMagnetic properties of ultrathin Fe and Fe60Au40, alloy films on Au (111) were studied by SQUID Magnetometry and conversion electron Mössbauer spectroscopy. In order to get information on the influence of interdiffusion, iron films with thin alloy zones at the interfaces to Au have been prepared by co-evaporation of iron and gold and compared with iron films with presumably sharp interfaces. It was found that the presence of an 0.5 ML (Mass coverage in Monolayer) alloy zone reduces the effective magnetic interface anisotropy field and affects the growth mode of a subsequently deposited iron film such that the film is more sensitive to annealing. Groundstate Magnetic Moments and hyperfine fields are significantly enhanced in Fe/Au(111) (tFe ≤ 4 ML) and Fe60Au40 films, compared to bulk Fe.

Magnetic Characteristics of RCo7−xZrx Alloys (invited) (R = Sm, Pr, Er, Gd, and Y)

1999 ◽  
Vol 577 ◽  
Author(s):  
M.Q. Huang ◽  
W.E. Wallace ◽  
M.E. Mchenry ◽  
S.G. Sankar ◽  
Qun Chen ◽  
...  
Keyword(s):  
Phase Transition ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Magnetic Moments ◽  
Anisotropy Field ◽  
Experimental Results ◽  
Magnetic Characteristics ◽  
Treatment Conditions ◽  
Experimental Values ◽  
Co Alloys

ABSTRACTA brief review is presented of recent work dealing with the structure and magnetic properties of RCo7−x Zrx alloys (R=Sm, Pr, Er, Gd, and Y). The experimental results obtained are consistent with a model in which Zr atoms partly replace dumbbell Co atoms and play an important role in stabilizing the TbCu7 structure while significantly increasing the anisotropy field (HA). For example, when R=Sm, HA increases from 90 kOe for x=O to 130 kOe for x=0.2 at 300 K, and from 140 kOe for x=0 to 220 kOe for x=0.2 at 10 K. In the case of R=Y and Gd, HA is mainly contributed by the Co sublattice. For R=Y alloys, HA increases from 18 kOe for x=0 to 74 kOe for x=0.2 at 300 K and from 20 kOe for x=0 to 82 kOe for x=0.2 at 10 K. For R=Gd alloys, HA shows the largest enhancement. It increases from 35 kOe for x=0 to 140 kOe for x=0.2 at 300 K and from planar for x=0 to uniaxial with 182 kOe for x=0.2 at 10 K. In general, experimental results are in accord with the theory of Greedan and Rao for anisotropies of R-Co alloys. The magnetic moments for cobalt and rare earth in RCo7−xrx compounds (x=0∼A).2) have been estimated from the experimental values. The results show that they are nearly the same as those in RCo5 or R2Co17. The Co moment is 1.5∼;1.6 μB. Some phase transition phenomenon between RCo5, RCo7, R2Co17and R2Co7at different heat treatment conditions will also be discussed.

An Influence of the Local Environment on Local Magnetic Moments and Hyperfine Fields in Fe3-xMnxAl

2006 ◽  
Vol 112 ◽  
pp. 117-122 ◽  
Author(s):  
Anna Go ◽  
Maria Pugaczowa-Michalska ◽  
Ludwik Dobrzyński
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Intermetallic Compound ◽  
Hyperfine Field ◽  
Magnetic Moment ◽  
Magnetic Moments ◽  
Local Environment ◽  
Hyperfine Fields ◽  
Type Crystal ◽  
Local Surrounding

Ferromagnetic, intermetallic compound Fe3Al exhibits DO3-type crystal structure. There are two non-equivalent types of iron with different chemical neighbourhood – (A,C) and B sublattices. As a consequence of the different nearest environments of the iron atoms at these sites the different electronic and magnetic properties connected with these positions are observed. The aim of our research is to investigate the influence of the local surrounding of the iron on its magnetic moment and hyperfine field in compound Fe3-xMnxAl where iron is substituted by manganese.

Fe-Ag Superlattices by Molecular Beam Epitaxy

1989 ◽  
Vol 151 ◽  
Author(s):  
S. H. Mayer ◽  
C. J. Gutierrez ◽  
J. C. Walker
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Energy ◽  
Squid Magnetometry ◽  
High Energy Electron ◽  
Hyperfine Fields ◽  
Iron Films ◽  
Linear Behavior ◽  
Growth System ◽  
Effusion Rates

ABSTRACTWe have succeeded in producing high quality (110)Fe/(111)Ag superlattices by Molecular Beam Epitaxy. Important parameters in the production of these materials were substrate temperature and effusion rates of the constituents. We have used SQUID magnetometry, Mössbauer spectroscopy and Reflection High Energy Electron Diffraction to demonstrate flatness and continuity of the films down to a thickness of approximately 2 atomic layers for the iron and 5 atomic layers for the silver. In the case of the thinnest iron layers, no large reduction of the ferromagnetic Curie temperature was observed, although this had been suggested and reported by other investigators. Furthermore, there was no indication for this particular growth system that the magnetization of the iron was out of the plane of the film. Variations of the magnetic hyperfine fields observed in the iron films were seen both as a function of iron thickness and as a function of the thickness of the intervening silver layers. For the thinnest films, the temperature dependence of the magnetization showed a linear behavior rather than the traditional T3/2 form.

Magnetic Properties and Microstructure of Co-Pt-B-O Alloy Films

1991 ◽  
Vol 232 ◽  
Author(s):  
K. Hayashi ◽  
Y. Iwasaki ◽  
A. Okabe ◽  
T. Yamamoto ◽  
M. Hayakawa ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Binary Alloy ◽  
Perpendicular Magnetic Anisotropy ◽  
Anisotropy Field ◽  
Close Correlation ◽  
Alloy Film ◽  
Column Diameter ◽  
Perpendicular Anisotropy ◽  
Alloy Films ◽  
Average Grain Size

ABSTRACTCo-Pt-B-O alloy films show the magnetic properties of saturation magnetic induction 4TπMs = 12 kG, perpendicular coercivity Hc(⊥) = 5 kOe, and perpendicular anisotropy field Hk(⊥) = 23 kOe. These characteristics are easily controlled by changing the film composition. The perpendicular magnetic anisotropy field and the coercivity of the Co-Pt-B-O alloy films have close correlation with the film microstructure. To clarify this relation, the individual effects of oxygen and boron in the Co-Pt binary alloy film were investigated. The addition of boron makes the average grain size smaller, whereas the column diameter remains unchanged. The addition of oxygen to the Co-Pt binary alloy reduces the column diameter to about 5–10 nm, whereas the columns are densely packed without any gaps. The sole addition of oxygen or boron neither increases the perpendicular anisotropy nor the coercivity. The high perpendicular anisotropy and the large coercivity are derived from the fine columnar structure of 5–10 nm in diameter coupled with the inter-columnar gaps of about 1 nm and are obtained by the co-additions of oxygen and boron.

Investigation and Effective Control of Perpendicular Magnetic Anisotropy for TbCo Films with Different Underlayers

SPIN ◽  
2016 ◽  
Vol 06 (03) ◽  
pp. 1650009 ◽  
Author(s):  
Minghong Tang ◽  
Shaohai Chen ◽  
Xiangli Zhang ◽  
Zongzhi Zhang ◽  
Q. Y. Jin
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Saturation Magnetization ◽  
Magnetic Moments ◽  
Perpendicular Magnetic Anisotropy ◽  
Effective Control ◽  
Experimental Measurements ◽  
Alloy Films ◽  
Micromagnetic Simulations

We performed a detailed study on the perpendicular magnetic anisotropy (PMA) of TbCo film by using two kinds of nonmagnetic underlayers, Ta and Ta/Cu with different thicknesses. We found that for both the Tb-rich and Co-rich TbCo alloy films, the PMA strength decreases considerably with the increase of Ta underlayer thickness, while their net saturation magnetization [Formula: see text] exhibit opposite varying trends. The [Formula: see text] value continues to increase for the Co-rich TbCo samples while decrease for the Tb-rich films. Interestingly, an additional Cu layer inserted between the Ta and TbCo layers can efficiently recover the PMA and [Formula: see text]. We attribute such observed variation behaviors of magnetic properties to the increased disordering of Tb magnetic moments at the Ta/TbCo interface, which has been verified by both experimental measurements and micromagnetic simulations.

scholarly journals Frequency dependence of microwave complex permeability under magnetic bias

2018 ◽  
Vol 185 ◽  
pp. 02019
Author(s):  
Artem O. Shiryaev ◽  
Stanislav Y. Bobrovskii ◽  
Aleksey V. Osipov ◽  
Dmitry A. Petrov ◽  
Konstantin N. Rozanov ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Frequency Dependence ◽  
Anisotropy Field ◽  
Measured Data ◽  
Sample Thickness ◽  
Complex Permeability ◽  
Correct Interpretation ◽  
Magnetic Bias ◽  
Iron Films ◽  
Nitrogen Doped

Measurement of the frequency dependence of the permeability under magnetic bias is proposed as a new method for studying the microwave magnetic properties of magnetic materials. The samples under study are either rolls of thin ferromagnetic films or the composites filled with sendust particles. It is shown that the permeability measured under external magnetic bias depends on sample thickness. The correct interpretation of the measured data is possible only when sample demagnetization is accounted for. The values of the anisotropy field and the saturation magnetization of thin nitrogen doped iron films and flake-shaped sendust particles are calculated considering demagnetization of the washer-shaped sample.

THE SOL–GEL SYNTHESIS OF RARE-EARTH IONS SUBSTITUTED BARIUM HEXAFERRITES AND MAGNETIC PROPERTIES

2013 ◽  
Vol 27 (26) ◽  
pp. 1350192 ◽  
Author(s):  
S. CAI ◽  
P. H. XIN ◽  
P. F. WANG ◽  
B. B. ZHANG ◽  
Y. B. HAN ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Magnetic Moments ◽  
Sol Gel ◽  
Barium Hexaferrite ◽  
Anisotropy Field ◽  
Average Diameter ◽  
Rare Earth Ions ◽  
Barium Hexaferrites ◽  
The Rare Earth

In this paper, a series of rare-earth-doped barium hexaferrite powders ( Ba 0.95 Re 0.05- Fe 12 O 19 and Ba 0.95 Re 0.05 M 0.05 Fe 11.95 O 19: Re = La , Pr , Sm , Nd , Gd , Dy , Yb ; M = Zn 2+, Mn 2+, [Formula: see text]) were synthesized by the sol–gel self-combustion technology. The phase composition and the magnetic properties of the as-prepared barium hexaferrites were characterized and discussed with X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The results showed that the barium hexaferrites exhibited the magnetoplumbite phase structure with the average diameter of 45 nm. Magnetic properties study revealed that the variation of the saturation magnetization (Ms) was similar with the change of the rare-earth ions radius, but the change of Ms was low. This indicated that the magnetic moments of rare-earth ions could not affect Ms. The magnetocrystalline anisotropy field mainly influenced the anisotropism of hexaferrites, and the coercivity (Hc) of the rare-earth ions doped barium hexaferrites basically decreased with the increasing orbital quantum numbers (except Sm 3+ and Gd 3+). Further study showed the co-addition of Zn 2+ and Mn 2+ did not change the trend of Ms and Hc. Thus, it is concluded that the rare-earth ions played an important role for the anisotropy field of barium hexaferrites.

scholarly journals Single Crystal Growth and Physical Properties of Pyroxene CoGeO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 378
Author(s):  
Li Zhao ◽  
Zhiwei Hu ◽  
Hanjie Guo ◽  
Christoph Geibel ◽  
Hong-Ji Lin ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Growth ◽  
Physical Properties ◽  
Single Crystal ◽  
Single Crystals ◽  
Magnetic Moments ◽  
Single Crystal Growth ◽  
The Impact

We report on the synthesis and physical properties of cm-sized CoGeO3 single crystals grown in a high pressure mirror furnace at pressures of 80 bar. Direction dependent magnetic susceptibility measurements on our single crystals reveal highly anisotropic magnetic properties that we attribute to the impact of strong single ion anisotropy appearing in this system with TN∼33.5 K. Furthermore, we observe effective magnetic moments that are exceeding the spin only values of the Co ions, which reveals the presence of sizable orbital moments in CoGeO3.

MAGNETIC PROPERTIES OF U1-xDyxAlyNi5-y (y=0,1) SYSTEMS

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1453-1460
Author(s):  
ILEANA LUPSA
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Spin Fluctuation ◽  
Magnetic Moments ◽  
Transition Temperatures ◽  
Temperature Range ◽  
Fluctuation Model ◽  
Magnetically Ordered

The magnetic properties of U 1-x Dy x Al y Ni 5-y (y=0,1) systems were investigated in the 2(5)–600 K temperature range and for fields up to 80 kOe. The systems having x≥0.2 are magnetically ordered with low transition temperatures and magnetization mainly due to the Dy contribution. The nickel exhibits magnetic moments, very weak in the low temperature range and well-defined effective moments over transition temperatures. The nickel behavior is discussed in terms of the spin fluctuation model.

Magnetic Properties of Embedded Rh Clusters in Ni Matrix

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Magnetic Moments ◽  
Functional Formalism ◽  
Rhodium Clusters ◽  
Spin Polarized ◽  
Local Density Functional

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.

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