Magnetic Properties of Rare-Earth/Fe Multilayered Films with Artificial Superstructures

1989 ◽  
Vol 151 ◽  
Author(s):  
Teruya Shinjo ◽  
Ko Mibu ◽  
Shinichi Ogawa ◽  
Nobuyoshi Hosoito

ABSTRACTBy using UHV deposition technique, multilayered films consisting of Fe and rare-earth (Dy, Nd or Y) layers were prepared. Magnetic properties of Fe layers were investigated from 57Fe Mössbauer spectroscopy. From SQUID magnetic measurements, the behavior of rare-earth layers was studied. In Fe/Dy and Fe/Nd multilayers, there often exists a large perpendicular anisotropy. Mössbauer spectra evidenced that, in certain samples, the magnetization changes the direction, from in-plane at high temperature to perpendicular at low temperature. The origin of the perpendicular anisotropy is attributed to interface rare-earth atoms which are magnetically coupled with ferromagnetic Fe layers even at higher than their bulk Curie temperatures.

1998 ◽  
Vol 51 (2) ◽  
pp. 201 ◽  
Author(s):  
G. J. Bowden

The rare earth vanadates have long been studied for their interesting magnetic properties and cooperative Jahn–Teller distortions. In the main, most of this work has been carried out at temperatures down to 1 K or so (e.g. Gehring and Gehring 1975). In this review NMRON, and other low temperature experiments in the mK regime, are presented and discussed. It will be argued that the low temperature properties of these compounds are just as interesting as their high temperature counterparts. In general, the nuclear and electronic wavefunctions become intermixed, leading to a variety of interesting physical effects, such as enhanced nuclear magnetism, quadrupolar induced intermediate state re-orientation etc. These effects have, in turn, spawned new methods for the investigation of magnetic structures, and thermometric detection of NMR both by internal and external thermometers. Several experiments are suggested, including magnetic refrigeration, Mössbauer, EPR in the ≈30 GHz range, in addition to thermometric NMR and NMRON.


1993 ◽  
Vol 313 ◽  
Author(s):  
G.A. Bertero ◽  
R.L. White ◽  
R. Sinclair

ABSTRACTWe have sputter-deposited a series of Pt/CO Multilayers with differing amounts of rare-earth (RE) in an effort to improve the uniaxial perpendicular anisotropy in these structures. The present work investigates the influence on the magnetic properties of Tb and Ho incorporated both at the interfaces of Pt/CO Multilayers and into the Co layers. The uniaxial anisotropy improved significantly only for those multilayers that showed poor perpendicular anisotropy in the undoped state, in particular, those with large (∼30 Å) bilayer periods. High resolution transmission electron microscopy was used to study these multilayers in cross-section. The Multilayer structures present strong [111] texture with grain sizes ranging from 200 to 600 Å. It is found that the RE does not produce a significant change in the growth texture of the multilayers until a critical amount is introduced beyond which the multilayer structure amorphizes resulting in a compositionally modulated amorphous film.


2016 ◽  
Vol 848 ◽  
pp. 709-714 ◽  
Author(s):  
Gang Fu ◽  
Jiang Wang ◽  
Mao Hua Rong ◽  
Guang Hui Rao ◽  
Huai Ying Zhou

The rare-earth (RE) permanent magnets based on Nd2Fe14B with excellent magnetic properties have been widely used in industrial applications. In this work, the crystal structure, microstructure and magnetic properties of Nd2.28Fe13.58B1.14, Ce2.28Fe13.58B1.14 and Pr2.28Fe13.58B1.14 alloys prepared by arc-melting were investigated. The results show that all alloys are single phase with tetragonal Nd2Fe14B-type (space group P42/mnm). The Curie temperatures (Tc) of RE2.28Fe13.58B1.14 (RE=Nd, Ce, Pr) alloys are 583 K, 423 K and 557 K, respectively. On the other hand, the coercivities of Nd2.28Fe13.58B1.14 and Pr2.28Fe13.58B1.14 alloys are about 1.05 T and 1.23 T, respectively, while that of Ce2.28Fe13.58B1.14 alloy is only about 0.25 T due to the poor squareness of hysteresis loop. Meanwhile, the saturation magnetizations of Nd2.28Fe13.58B1.14 and Pr2.28Fe13.58B1.14 alloys are about 135 emu/g and 113 emu/g, respectively, while that of Ce2.28Fe13.58B1.14 alloy is about 97 emu/g. It was indicated that the Curie temperatures and magnetic properties of RE2.28Fe13.58B1.14 alloys with the same crystal structure are dependent on light rare earth elements.


2014 ◽  
Vol 664 ◽  
pp. 57-61
Author(s):  
Jing Yuan Guo ◽  
Qiang Tang ◽  
Li Gao ◽  
Ting Ting Lan ◽  
Chun Xiang Zhang ◽  
...  

In this paper, MgSO4:Dy,MgSO4:Tm and MgSO4:Mn phosphors are prepare by high temperature solid state reaction. The MgSO4:Dy or MgSO4:Tm powder are mixed and sintered with MgSO4:Mn respectively to obtain the co-doped MgSO4:Dy,Mn and MgSO4:Tm,Mn phosphors. The 3-dimensional thermoluminescence spectra of these two phosphors under different sintering temperature are measured.Results show that when the sintering temperature is below 800°C, Dy, Tm and Mn ions emissions are independent. However, when the sintering temperature was over 800°C, the emission peak of Mn becomes weaker, and so do the low temperature peaks of Dy and Tm, while the high temperature peaks of Dy and Tm become stronger. This indicated that the defect complex structure in the formation of the thermoluminescence material depends on the sintering temperature. As the sintering temperature rises, more and more Mn ions combine with the rare earth ions. Therefore, the luminescence process of the energy transfer of Mn ions to the rare earth ions can be observed and the suppression to low temperature peaks of Tm and Dy, and also shown in spectra.


2010 ◽  
Vol 82 (22) ◽  
Author(s):  
Jun Sugiyama ◽  
Yutaka Ikedo ◽  
Kazuhiko Mukai ◽  
Hiroshi Nozaki ◽  
Martin Månsson ◽  
...  

2015 ◽  
Vol 24 (11) ◽  
pp. 115025 ◽  
Author(s):  
Saif Ullah Awan ◽  
S K Hasanain ◽  
Zahid Mehmood ◽  
D H Anjum ◽  
Saqlain A Shah ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1209
Author(s):  
Xin Tian ◽  
Shuang Kuang ◽  
Jie Li ◽  
Shuai Liu ◽  
Yunli Feng

In this study, the effects of decarburization annealing time on the primary recrystallization microstructure, the texture and the magnetic properties of the final product of 0.047% Nb low-temperature grain-oriented silicon steel were investigated by means of OM, EBSD and XRD. The results show that when the decarburization annealing condition is 850 °C for 5 min, the uniform fine primary recrystallization microstructure can be obtained, and the content of favorable texture {111} < 112 > is the highest while that of unfavorable texture {110} < 112 > is the lowest, which is mostly distributed near the central layer. At the same time, there are the most high-energy grain boundaries with high mobility in the primary recrystallization microstructure of the sample annealed at 850 °C for 5 min, and the ∑9 boundary has the highest percentage of grain boundaries. The samples with different decarburization annealing time were annealed at high temperature. It was found that perfect secondary recrystallization occurred after high-temperature annealing when the decarburization annealing condition was 850 °C for 5 min. The texture component was characterized by a single Goss texture, and the size of the Goss grain reached 4.6mm. Under such annealing conditions, the sample obtained shows the optimal soft magnetic properties of B800 = 1.89T and P1.7/50 = 1.33 w/kg.


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