MAGNETIC PROPERTIES OF SUPERCONDUCTING nMBa2Cu3Ox:Ag (M = Y, Gd, and Eu) COMPOSITES

1989 ◽  
Vol 03 (16) ◽  
pp. 1251-1265
Author(s):  
C. Y. HUANG ◽  
T. J. LI ◽  
Y. D. YAO ◽  
L. GAO ◽  
Z. J. HUANG ◽  
...  

We measured the M-H hysteresis loops of n YBa 2 Cu 3 O x: Ag (n = 3, 5, and 7) and 3RBa 2 Cu 3 O x: Ag (R = Gd and Eu) as a function of temperature, and found that the residual magnetization and, hence, pinning is independent of n and the rare-earth ions (R and Y), but depends greatly on the processing conditions. These samples exhibit the strongest pinning force for high-temperature superconductors developed to date.

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.


2015 ◽  
Vol 05 (04) ◽  
pp. 1520001 ◽  
Author(s):  
Radheshyam Rai ◽  
Poonam Kumari ◽  
M. A. Valente

In this paper, we investigated the influence of rare earth ([Formula: see text] and Gd) doped Ba[Formula: see text]RE[Formula: see text]Ca[Formula: see text]Ti[Formula: see text] Mn[Formula: see text]Nb[Formula: see text]Zr[Formula: see text]O3 (BCTMNZ) ceramics were fabricated by using a conventional solid-state reaction method. The doping effects of La and Gd on the structural and magnetic properties were studied. The structural pattern of the ceramic samples were investigated by X-ray diffraction and the results indicated that both samples shows an orthorhombic structure with pure phase. Strain and crystalline size values for Gd and La doped were 0.31–0.33% and [Formula: see text]–[Formula: see text]m, respectively. The room temperature hysteresis loops were obtained by using a vibrating sample magnetometer. La doped ceramic showed the higher value of magnetization i.e., [Formula: see text]B/f.u. as compared to Gd doped BLTMNZ ceramics.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 972
Author(s):  
Natalia Tsidaeva ◽  
Ahsarbek Nakusov ◽  
Spartak Khaimanov ◽  
Wei Wang

In this study, the synthesis and magnetic properties of the rare-earth iron garnets Sm3Fe5O12, Pr3Fe5O12, and Er3Fe5O12 (in the form of powders and thin films) are reported. According to the composition, shape, and size of particles, the optimal precipitant for the synthesis of Sm3Fe5O12, Pr3Fe5O12, and Er3Fe5O12 films is an aqueous solution. The parameters for the synthesis of powders and films of the rare-earth iron garnets with micro- and nano-particles have been investigated and selected. The magnetic properties of these materials were studied; field dependencies of the magnetic moment (hysteresis loops) of nanostructured powders of iron garnets of samarium, praseodymium, and erbium in the range of +20 kOe to −20 kOe were obtained. The structural features of the Al2O3 substrate on which the films were formed are also shown.


2013 ◽  
Vol 27 (26) ◽  
pp. 1350192 ◽  
Author(s):  
S. CAI ◽  
P. H. XIN ◽  
P. F. WANG ◽  
B. B. ZHANG ◽  
Y. B. HAN ◽  
...  

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.


1970 ◽  
Vol 24 (4) ◽  
pp. 436-445 ◽  
Author(s):  
G. V. Subba Rao ◽  
C. N. R. Rao ◽  
J. R. Ferraro

The electronic and ir spectra of rare earth perovskites of the general formula LnZO3, where Ln is the rare earth ion or yttrium and Z is Cr, Mn, or Fe, have been studied in detail. The results have been discussed in terms of crystallography, magnetic properties, covalency of Ln—O and Z—O bonds, and Goodenough's one electron energy diagrams. In all these compounds the rare earth ions do not markedly affect the electronic transitions of the transition metal ions; the 3 d electrons clearly exhibit localized behavior. Both the electronic and ir spectra of the LnZO3 perovskites are comparable to the spectra of the corresponding transition metal sesquioxides, Z2O3.


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.


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