scholarly journals Магнитная восприимчивость нанокомпозитных редкоземельных титанатов в переменных полях

2020 ◽  
Vol 62 (12) ◽  
pp. 2062
Author(s):  
А.Б. Ринкевич ◽  
Д.В. Перов
Keyword(s):  
Experimental Investigation ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Low Temperatures ◽  
Ac Susceptibility ◽  
Relaxation Times ◽  
Frequency Range ◽  
Debye Formula ◽  
Spherical Voids ◽  
Frequency Dependences

Experimental investigation of magnetic susceptibility of nanocomposite rare earth titanates at low temperatures is carried out in frequency range from 1 Hz to 10 kHz. Nanocomposites based on opal matrices are the objects under study which inter-spherical voids are filled with Gd2Ti2O7, Yb2Ti2O7, Dy2Ti2O7 и Dy2Si2O7 particles sized up to 60 nm. The frequency dependences of AC susceptibility are measured at temperatures from 2 to 20K. At frequencies above 1 kHz the frequency dependence fairly good corresponds to a relaxing oscillator model and can be approximated by Debye formula for all nanocomposites. For frequencies from 1 Hz to 10 kHz, however, it is necessary to apply a model with two relaxation times.

Ternary rhombohedral Laves phases RE2Rh3Ga (RE = Y, La–Nd, Sm, Gd–Er)

2017 ◽  
Vol 72 (4) ◽  
pp. 289-303 ◽  
Author(s):  
Stefan Seidel ◽  
Oliver Janka ◽  
Christopher Benndorf ◽  
Bernhard Mausolf ◽  
Frank Haarmann ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Low Temperatures ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
Laves Phases ◽  
X Ray ◽  
Arc Melting ◽  
Pauli Paramagnetism

Abstract:The ordered Laves phases RE2Rh3Ga (RE=Y, La–Nd, Sm, Gd–Er) were synthesized by arc-melting of the elements and subsequent annealing. The samples were characterized by powder X-ray diffraction (XRD). They crystallize with the rhombohedral Mg2Ni3Si type structure, space group R3̅m. Three structures were refined from single crystal X-ray diffractometer data: a=557.1(1), c=1183.1(2), wR2=0.0591, 159 F2 values, 10 variables for Y2Rh3Ga, a=562.5(2), c=1194.4(2) pm, wR2=0.0519, 206 F2 values, 11 variables for Ce2Rh3Ga and a=556.7(2), c=1184.1(3) pm, wR2=0.0396, 176 F2 values, 11 variables for Tb2Rh3Ga. The Rh3Ga tetrahedra are condensed via common corners and the large cavities left by the network are filled by the rare earth atoms. The RE2Rh3Ga Laves phases crystallize with a translationengleiche subgroup of the cubic RERh2 Laves phases with MgCu2 type. Magnetic susceptibility measurements reveal Pauli paramagnetism for Y2Rh3Ga and La2Rh3Ga. Ce2Rh3Ga shows intermediate cerium valence while all other RE2Rh3Ga phases are Curie–Weiss paramagnets which order magnetically at low temperatures. The 89Y and 71Ga solid state nuclear magnetic resonance (NMR) spectra of the diamagnetic representative Y2Rh3Ga show well-defined single resonances in agreement with an ordered bulk phase. In comparison to the binary Laves phase YRh2 a strongly increased 89Y resonance frequency is observed owing to a higher s-electron spin density at the 89Y nuclei as proven by density of states (DOS) calculations.

Observation of Dielectric Peaks in Glassy Se70Te20Sn10 Alloy

2012 ◽  
Vol 329 ◽  
pp. 165-175 ◽  
Author(s):  
A. Sharma ◽  
N. Mehta
Keyword(s):  
Chalcogenide Glasses ◽  
Relaxation Times ◽  
Dielectric Dispersion ◽  
Dielectric Constants ◽  
Audio Frequency ◽  
Frequency Range ◽  
Glass Transition Region ◽  
Dipolar Relaxation ◽  
The Past ◽  
Frequency Dependences

The Temperature and Frequency Dependences of the Dielectric Constants () and Dielectric Loss (") Were Studied in Glassy Se70Te20Sn10Alloy in the Audio-Frequency Range below the Glass Transition Region. the Results Indicated that Dielectric Dispersion Occurred in Glassy Se70Te20Sn10Alloy. Well-Defined Dielectric Peaks Were Obtained in Glassy Se70Te20Sn10Alloy; these Are Rarely Observed in Chalcogenide Glasses. such Loss Peaks Were Not Observed in the Glassy Se80-xTe20SnxSystem in the past for Sn Concentrations of x ≤ 8. A Detailed Analysis of the Data Showed that the Results Could Be Explained in Terms of Dipolar Relaxation, with a Distribution of Relaxation Times, this Is Quite Expected in the Case of Chalcogenide Glasses.

scholarly journals DIELECTRIC RELAXATION IN POR-SI LAYERS AT LOW FREQUENCIES

2020 ◽  
pp. 170-179
Author(s):  
Юлия Михайловна Спивак ◽  
Арата Рене Алехандро Кастро ◽  
Мария Павловна Севрюгина ◽  
Мария Александровна Кузнецова ◽  
Вячеслав Алексеевич Мошников
Keyword(s):  
Surface Layer ◽  
Relaxation Times ◽  
Relaxation Mechanism ◽  
Point Of View ◽  
Macroporous Silicon ◽  
Nanostructured Surface ◽  
Frequency Range ◽  
Porous Si ◽  
Low Frequencies ◽  
Frequency Dependences

Методом электрохимического анодного травления получен макропористый кремний с высокоомным мезопористым наноструктурированным «скин»-слоем на поверхности. Измерения частотных зависимостей диэлектрических коэффициентов полученных слоев пористого Si выполнены в частотном интервале 5⋅10 < f < 10 Гц при температуре 295 К и приложенном напряжении 1 В. Выявлен максимум тангенса угла диэлектрических потерь, который, наиболее вероятно, обусловлен преобладанием дипольно-релаксационного механизма поляризации. Обнаружено распределение релаксаторов по временам релаксации, предложена интерпретация полученных результатов с точки зрения строения пористого слоя. Macroporous silicon with a mesoporous nanostructured surface layer on top was obtained by the method of electrochemical anodic etching. The frequency dependences of the dielectric coefficients for porous Si layers were measured in the frequency range 5⋅10 < f < 10 Hz at a temperature of 295 K and an applied voltage of 1 V. A maximum of the dielectric loss tangent is revealed, which is most likely due to the predominance of the dipole relaxation mechanism of polarization. The distribution of relaxers over relaxation times has been. An interpretation of the results obtained from the point of view of the structure of the porous layer is proposed.

Magnetic susceptibility of liquid heavy rare earth metals

1979 ◽  
Vol 40 (C5) ◽  
pp. C5-260-C5-261 ◽  
Author(s):  
M. Müller ◽  
E. Huber ◽  
H.-J. Güntherodt
Keyword(s):  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Rare Earth Metals ◽  
Heavy Rare Earth

scholarly journals Experimental Investigation of WE54 magnesium rare earth metal alloys by ageing treatment

2021 ◽  
Vol 1104 (1) ◽  
pp. 012025
Author(s):  
Sachendra ◽  
Shailesh Kumar Singh ◽  
Ujjwal ◽  
Satyajeet Kumar ◽  
Kuldeep Singh
Keyword(s):  
Experimental Investigation ◽  
Rare Earth ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Metal Alloys ◽  
Ageing Treatment

scholarly journals New Radical Cation Salts Based on BDH-TTP Donor: Two Stable Molecular Metals with a Magnetic [ReF6]2− Anion and a Semiconductor with a [ReO4]− Anion

2021 ◽  
Vol 7 (4) ◽  
pp. 54
Author(s):  
Nataliya D. Kushch ◽  
Gennady V. Shilov ◽  
Lev I. Buravov ◽  
Eduard B. Yagubskii ◽  
Vladimir N. Zverev ◽  
...  
Keyword(s):  
Radical Cation ◽  
Low Temperatures ◽  
Ac Susceptibility ◽  
Slow Relaxation ◽  
Organic Radical ◽  
Inorganic Anion ◽  
Distinctive Features ◽  
Metallic Character ◽  
Radical Cation Salts ◽  
Partial Population

Three radical cation salts of BDH-TTP with the paramagnetic [ReF6]2− and diamagnetic [ReO4]− anions have been synthesized: κ-(BDH-TTP)4ReF6 (1), κ-(BDH-TTP)4ReF6·4.8H2O (2) and pseudo-κ″-(BDH-TTP)3(ReO4)2 (3). The crystal and band structures, as well as the conducting properties of the salts, have been studied. The structures of the three salts are layered and characterized by alternating κ-(1, 2) and κ″-(3) type organic radical cation layers with inorganic anion sheets. Similar to other κ-salts, the conducting layers in the crystals of 1 and 2 are formed by BDH-TTP dimers. The partial population of positions of Re atoms and disorder in the anionic layers of 1–3 are their distinctive features. Compounds 1 and 2 show the metallic character of conductivity down to low temperatures, while 3 is a semiconductor. The ac susceptibility of crystals 1 was investigated in order to test the possible slow relaxation of magnetization associated with the [ReF6]2− anion.

Thermorheological Characterization of Elastoviscoplastic Carbopol Ultrez 20 Gel

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
M. A. Hassan ◽  
Manabendra Pathak ◽  
Mohd. Kaleem Khan
Keyword(s):  
Experimental Investigation ◽  
Yield Stress ◽  
Elastic Properties ◽  
Viscous Dissipation ◽  
Power Law ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
Frequency Range ◽  
Power Law Index

The temperature and concentration play an important role on rheological parameters of the gel. In this work, an experimental investigation of thermorheological properties of aqueous gel Carbopol Ultrez 20 for various concentrations and temperatures has been presented. Both controlled stress ramps and controlled stress oscillatory sweeps were performed for obtaining the rheological data to find out the effect of temperature and concentration. The hysteresis or thixotropic seemed to have negligible effect. Yield stress, consistency factor, and power law index were found to vary with temperature as well as concentration. With gel concentration, the elastic effect was found to increase whereas viscous dissipation effect was found to decrease. Further, the change in elastic properties was insignificant with temperature in higher frequency range of oscillatory stress sweeps.

Magnetic susceptibility of a linear chain antiferromagnet, TANOL, at very low temperatures

1976 ◽  
Vol 41 (2) ◽  
pp. 354-356 ◽  
Author(s):  
Masafumi Kumano ◽  
Yusaku Ikegami ◽  
Takashi Sato ◽  
Shinhachiro Saito
Keyword(s):  
Magnetic Susceptibility ◽  
Low Temperatures ◽  
Linear Chain

MAGNETIC BEHAVIOUR OF UPdAl, UCuGa AND UCuSn

1993 ◽  
Vol 07 (01n03) ◽  
pp. 850-854 ◽  
Author(s):  
V.H. TRAN ◽  
R. TROĆ
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Low Temperatures ◽  
Magnetic Behaviour ◽  
Type Structure ◽  
Complex Structures ◽  
Temperature Dependent ◽  
Antiferromagnetic Ordering

Magnetic susceptibility and electrical resistivity have been measured on UCuGa, UCu1+xSn1−x, (x=0 and 0.1), and UPdAl. The first two compounds, crystallizing in the hexagonal CaIn2-type structure, show at low temperatures an antiferromagnetic ordering probably with complex structures. UPdAl, which adopts the orthorhombic TiNiSi-type structure, was found to be a weakly temperature-dependent paramagnet down to 4.2 K.

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