scholarly journals A Review of the Low Temperature Properties of the Rare Earth Vanadates

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.

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.


1993 ◽  
Vol 07 (01n03) ◽  
pp. 818-821 ◽  
Author(s):  
D. RAVOT ◽  
O. GOROCHOV ◽  
T. ROISNEL ◽  
G. ANDRE ◽  
F. BOUREE-VIGNERON ◽  
...  

For all the Rare-Earth (R) the R2In form in the same crystal structure (P63/mmc). These compounds show a great variety of magnetic behaviors. When the temperature decreases, the magnetic susceptibility of Er2InTb2In and Gd2In increases, passes through a maximum then decreases. For Gd2In this behavior was associated with change from a paramagnetic to a ferromagnetic then to an antiferromagnetic state. We have performed magnetic, transport (Tb, Er), Mössbauer spectroscopy (Er) and powder neutron diffraction experiments (Gd, Tb, Er) on these compounds. Unlike Gd2In the resistivity of Tb2In and Er2In does not reveal any anomaly at the temperature where the susceptibility begins to decrease and the Tb2In and Er2In magnetizations show the same behavior at all temperatures in the ordered region. Neutron diffraction experiments reveal ferromagnetic and antiferromagnetic structures at low temperature.


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.


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.


2020 ◽  
Vol 29 (5) ◽  
pp. 057503
Author(s):  
Jie-Ming Sheng ◽  
Xu-Cai Kan ◽  
Han Ge ◽  
Pei-Qian Yuan ◽  
Lei Zhang ◽  
...  

2008 ◽  
Vol 47 (23) ◽  
pp. 11048-11056 ◽  
Author(s):  
Andrea M. Goforth ◽  
Peter Klavins ◽  
James C. Fettinger ◽  
Susan M. Kauzlarich

1993 ◽  
Vol 48 (9) ◽  
pp. 6217-6224 ◽  
Author(s):  
B. I. Min ◽  
J.-S. Kang ◽  
J. H. Hong ◽  
J. I. Jeong ◽  
Y. P. Lee ◽  
...  

1979 ◽  
Vol 18 (4) ◽  
pp. 385-394
Author(s):  
J. Urrutia Fucugauchi

El presente trabajo se basa en resultados de elementos de tierras raras obtenidas en basaltos toleíticos provenientes de la boca del Golfo de California, México. Los basaltos fueron muestreados durante una operación de dragado en la latitud de 23° N.Los elementos de tierras raras fueron obtenidos por el método instrumental de activación por neutrones (López et al.. 1978). Las muestras fueron tomadas entre la cresta de la Dorsal de Pacífico Este y la plataforma continental de la península de Baja California. Las edades asignadas a las muestras con base en datos de anomalías magnéticas y de la relación batimetría edad del fondo oceánico son de 0, 1.7 y 3.5 millones de años. Los datos son empleados en este trabajo para evaluar el comportamiento de las tierras raras durante procesos de alteración a bajas temperaturas. Fue usado un procedimiento de normalización propuesto por Ludden y Thompson (1978) para datos de basaltos en la dorsal del Atlántico Medio (23°N). No obstante que el valor de la normalización (esto es, la abundancia de Yb para basaltos sin alteración) puede no ser válido para los basaltos de la Dorsal de Pacífico Este (23°N), los resultados obtenidos son consistentes y reflejan los efectos de alteración. Dichos resultados están de acuerdo con el modelo propuesto por Ludden y Thompson. Las muestras reflejan un enriquecimiento progresivo de las tierras raras ligeras (La a Sm) con la alteración (edad). Por otro lado, las diferencias observadas con respecto a los resultados anteriores indican que las tierras raras no se comportaran se igual forma en todos los ambientes de alteración. En particular, el elemento Ce muestra anomalías positivas y negativas. El agua de mar tiene una anomalía negativa, de aquí que este comportamiento puede ser interpretado en términos de la abundancia de Ce en el agua de mar o bien su fraccionamiento del agua de mar.


Sign in / Sign up

Export Citation Format

Share Document