scholarly journals Phase Diagrams of the Excitonic Insulator State: Analyzing the Excitonic Susceptibility

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Thi Hong Hai DO ◽  
Thi Hau NGUYEN
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Phase Diagrams ◽  
Coulomb Interaction ◽  
External Pressure ◽  
Model Parameters ◽  
Excitonic Insulator ◽  
Self Consistent ◽  
The Rare Earth ◽  
System Analyzing

In this paper, the formation of the excitonic insulator state in the rare-earth chalcogenides hasbeen investigated through the extended Falicov-Kimball model. Adapting the unrestricted Hartree-Fockapproximation, we have derived a set of explicitly self-consistent equations determining expectationvalues and the excitonic susceptibility in the system. Analyzing the excitonic susceptibility, we haveestablished phase diagrams of the excitonic insulator state depending on the model parameters. The phasestructures confirmed the excitonic insulator state is found at low temperature and between two criticalvalues of the Coulomb interaction. The effect of the external pressure on the formation of the excitonicinsulator state is also shown.

Low temperature magnetism in the rare-earth perovskite GdScO3

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

scholarly journals EFFECTS OF THE LOW TEMPERATURE SEA-FLOOR WEATHERING ON THE RARE EARTH ELEMENTS OF THOLEIITIC BASALTS

1979 ◽  
Vol 18 (4) ◽  
pp. 385-394
Author(s):  
J. Urrutia Fucugauchi
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Rare Earth Elements ◽  
Baja California ◽  
Sea Floor ◽  
The Rare Earth

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.

scholarly journals Low-temperature magnetostriction and distortions in the rare-earth Laves phases

2019 ◽  
Vol 1389 ◽  
pp. 012097
Author(s):  
G Politova ◽  
M Ganin ◽  
T Kaminskaya ◽  
A Mikhailova ◽  
B Nacke ◽  
...  
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Laves Phases ◽  
The Rare Earth

Low‐Temperature Thermoelectric Power of the Rare‐Earth Metals

1961 ◽  
Vol 32 (12) ◽  
pp. 2543-2549 ◽  
Author(s):  
H. J. Born ◽  
Sam Legvold ◽  
F. H. Spedding
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Thermoelectric Power ◽  
Rare Earth Metals ◽  
The Rare Earth

Influence of Sintering Temperature on the Thermoluminescence Spectra of MgSO4 Doped with RE(Tm,Dy) and Mn

2014 ◽  
Vol 664 ◽  
pp. 57-61
Author(s):  
Jing Yuan Guo ◽  
Qiang Tang ◽  
Li Gao ◽  
Ting Ting Lan ◽  
Chun Xiang Zhang ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Temperature ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Complex Structure ◽  
Rare Earth Ions ◽  
3 Dimensional ◽  
Luminescence Process ◽  
Co Doped ◽  
The Rare Earth

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.

Low-temperature phase transitions in the rare-earth ferroborate Nd0.75Dy0.25Fe3(BO3)4

2010 ◽  
Vol 36 (3) ◽  
pp. 279-281 ◽  
Author(s):  
G. A. Zvyagina ◽  
K. R. Zhekov ◽  
I. V. Bilych ◽  
A. A. Zvyagin ◽  
L. N. Bezmaternyhk ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phase Transitions ◽  
Low Temperature ◽  
Temperature Phase ◽  
Low Temperature Phase ◽  
The Rare Earth

MAGNETIC PROPERTIES OF R2In (R=Gd, Tb, Er)

1993 ◽  
Vol 07 (01n03) ◽  
pp. 818-821 ◽  
Author(s):  
D. RAVOT ◽  
O. GOROCHOV ◽  
T. ROISNEL ◽  
G. ANDRE ◽  
F. BOUREE-VIGNERON ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Low Temperature ◽  
Neutron Diffraction ◽  
Antiferromagnetic State ◽  
Powder Neutron Diffraction ◽  
Magnetic Transport ◽  
The Rare Earth

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.

Sign in / Sign up

Export Citation Format

Share Document