Studies of the ionic ferromagnet (LaPb)MnO3 III. Ferromagnetic resonance studies

1969 ◽  
Vol 47 (23) ◽  
pp. 2703-2708 ◽  
Author(s):  
C. W. Searle ◽  
S. T. Wang
Keyword(s):  
Critical Temperature ◽  
Conduction Band ◽  
Ferromagnetic Resonance ◽  
Low Temperatures ◽  
Resonance Line ◽  
Isotropic Shift ◽  
Sharp Minimum ◽  
Asymmetric Behavior ◽  
Spin Polarized ◽  
The Family

Ferromagnetic resonance has been observed in single crystals of the family La1−xPbxMnO3with 0.25 < x < 0.45 from 13 to 25 GHz and in the temperature range from 77 to 430 °K. The line width, ΔH, exhibits a sharp minimum accompanied by an isotropic shift in the resonance line at a critical temperature, Tc. Tc is dependent on the concentration of Mn4+ and has been related to the Curie temperature. The shift in the peak of the resonance line at Tc can be described by effects related to the formation of a spin-polarized conduction band. The line shape is asymmetric at high temperatures, ~Tc, and at low temperatures, T ~ 77 °K. This asymmetric behavior of the line is probably due to transport properties of the conduction-band electrons.

Studies of the Ionic Ferromagnet (LaPb)MnO3. VI. Antiresonance and the Ferromagnetic Resonance Line Shape

1971 ◽  
Vol 49 (3) ◽  
pp. 387-390 ◽  
Author(s):  
S. T. Wang ◽  
C. W. Searle
Keyword(s):  
Line Width ◽  
Ferromagnetic Resonance ◽  
Line Shape ◽  
Qualitative Agreement ◽  
Resonance Line ◽  
Skin Depth ◽  
Frequency Range ◽  
The Family

The resonance line shape and line width of the family La(1−x)PbxMnO3 have been examined from 77 to 430 °K in a frequency range from 13 to 25 GHz. The distorted line shape is in qualitative agreement with a calculation that includes the effect of the skin depth. The antiresonance condition has been observed and it is also in qualitative agreement with theory.

High Spin Polarization of Conduction Band Electrons in GaAs-GaAsP Strained Layer Superlattice Fabricated as a Spin-Polarized Electron Source

2004 ◽  
Vol 43 (6A) ◽  
pp. 3371-3375 ◽  
Author(s):  
Tetsuya Matsuyama ◽  
Hisaya Takikita ◽  
Hiromichi Horinaka ◽  
Kenji Wada ◽  
Tsutomu Nakanishi ◽  
...  
Keyword(s):  
Conduction Band ◽  
Spin Polarization ◽  
High Spin ◽  
Electron Source ◽  
Strained Layer ◽  
Spin Polarized ◽  
High Spin Polarization ◽  
Strained Layer Superlattice

scholarly journals ACCUMULATION BEHAVIOUR OF ALLANTOIN IN THE UNDERGROUND PHYTOMASS OF THE BORAGINACEAE FAMILY AND ITS ROLE IN ADAPTING THE PLANTS TO ADVERSE ENVIRONMENTAL FACTORS

2019 ◽  
Vol 14 (1) ◽  
pp. 126-136
Author(s):  
A. Ya. Tamakhina ◽  
A. A. Akhkubekova ◽  
A. B. Ittiev
Keyword(s):  
Solar Radiation ◽  
Sea Level ◽  
Low Temperatures ◽  
High Performance ◽  
Growing Season ◽  
Stress Factors ◽  
Adaptation To Stress ◽  
Plant Adaptation ◽  
The Family

Aim.The aim of the work described herein was to study the dynamics of allantoin accumulation in the underground phytomass ofEchium vulgareL.,Symphytum caucasicumM. Bieb. andS. asperumLepech. as well as to clarify the role of allantoin in plant adaptation to stress factors.Methods.We studied the roots of plants growing in the foothill (Nalchik, 490–512 m above sea level) and the mountain zones of the Kabardino-Balkarian Republic (Terskol village, 2530 m above sea level; Verkhnyaya Balkaria village, 2680 m above sea level). The roots were collected at the stages of rosetting, flowering, fruiting and at the end of the growing season. Aqueous-alcoholic extracts of shredded roots were analyzed by high-performance liquid chromatography.Results.The highest content of allantoin in the roots ofEchium vulgare,Symphytum caucasicum,S. asperumplants was noted at the end of the growing season, respectively 0.915; 0.342–0.658; 2,842–3,426%. Under conditions of low temperatures and increased solar radiation, the content of allantoin in the roots increases 1.2–1.9 times as compared with the plants of the foothill zone.Conclusion.Allantoin plays an important role in the process of adapting species of the family Boraginaceae to oxidative stress caused by hypothermia and increased solar radiation.

scholarly journals Laboratory Metabolism of Incubating Semipalmated Plovers

The Condor ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 966-970
Author(s):  
Mark Williamson ◽  
Joseph B. Williams ◽  
Erica Nol
Keyword(s):  
Critical Temperature ◽  
Metabolic Rate ◽  
Breeding Season ◽  
Basal Metabolic Rate ◽  
Low Temperatures ◽  
Thermal Conductance ◽  
Basal Metabolism ◽  
The Arctic ◽  
Lower Critical Temperature ◽  
Metabolic Data

Abstract Abstract The Semipalmated Plover (Charadriussemipalmatus), anarctic-nesting migratory shorebird, regularlyencounters low temperatures during the breedingseason. We measured the basal metabolism of adultsduring incubation at Churchill, Manitoba, Canada todetermine basal metabolic rate (BMR),lower critical temperature(Tlc), total evaporative waterloss (TEWL), and dry thermal conductance(Cm). BMR and Tlcwere 47.4 kJ day−1and 23.3°C, respectively, TEWL was2.5 mL H2O−d,and Cm was1.13 mW g−1 °C−1.Measured BMR and Tlc were consistentwith high values found for other shorebird speciesbreeding in the Arctic, while Cm was18% higher than predicted from allometricequations. These metabolic data suggest thatSemipalmated Plovers are adapted to balance therequirements of incubation against energetic andthermoregulatory demands in the Arctic, especiallyin harsh early breeding season conditions.

Possible Bose-Einstein Condensation of Polygonal Clusters in 2D-Materials

2019 ◽  
Vol 297 ◽  
pp. 204-208
Author(s):  
Abid Boudiar
Keyword(s):  
Free Energy ◽  
Critical Temperature ◽  
Ground State ◽  
Low Temperatures ◽  
2D Materials ◽  
Equilibrium Structure ◽  
Einstein Condensation ◽  
Bose Einstein Condensation ◽  
Exchange Approximation ◽  
Bose Einstein

This study investigates the possibility of Bose-Einstein condensation (BEC) in 2D-nanoclusters. A ground state equilibrium structure involves the single phonon exchange approximation. At critical temperature, the specific heat, entropy, and free energy of the system can be determined. The results support the existence of BEC in nanoclusters, and they lead to predictions of the behaviour of 2Dmaterials at low temperatures.

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