The Influence of Magnetic Inhomogeneous State on Thermopower and Magnetothermopower in Sm0.55Sr0.45MnO3 Manganites

2014 ◽  
Vol 215 ◽  
pp. 320-324
Author(s):  
Liudmila I. Koroleva ◽  
Artiom S. Morozov ◽  
Elina S. Zhakina
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Charge Order ◽  
Inhomogeneous State ◽  
Néel Temperature ◽  
Oxygen Ions ◽  
Sharp Minimum ◽  
Large Maximum

Thermopower α and magnetothermopower α/α were studied in the single-crystal Sm0.55Sr0.45MnO3 samples, containing clusters of three types: ferromagnetic clusters with the Curie temperature TC = 134 K, A-type antiferromagnetic clusters with the Neel temperature TNATC and CE-type antiferromagnetic clusters with the TNCE = 240 K. The curves of temperature dependence of α (T) and {α/α}(T) have extrema in the TNCE-region: large maximum on the first and sharp minimum on the second. Negative magnetothermopower in minimum achieves the giant value 50% in magnetic field 13,2 kOe. It is shown that thermopower is essentially caused by the presence of CE-type antiferromagnetic clusters, in which exists charge order, displacing oxygen ions

Giant Magnetothermopower in Sm0.55Sr0.45MnO3 Manganite

2015 ◽  
Vol 233-234 ◽  
pp. 141-144
Author(s):  
Liudmila I. Koroleva ◽  
Artiom S. Morozov ◽  
E.S. Zhakina
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Temperature Dependence ◽  
Charge Ordering ◽  
Neel Temperature ◽  
Néel Temperature ◽  
Oxygen Ions ◽  
Sharp Minimum ◽  
Large Maximum ◽  
A Charge

Thermopower α and magnetothermopower ∆α/α were studied in the Sm0.55Sr0.45MnO3 samples, containing clusters of three types: ferromagnetic clusters with the Curie temperature TC = 126 K, A-type antiferromagnetic clusters with the Neel temperature TNA ≥ TC and CE-type antiferromagnetic clusters with the TNCE = 240 K. The curves of temperature dependence of α (T) have a large maximum including TC and TNCE and the sharp minimum on the {∆α/α}(T) curves in the TC-region. Negative magnetothermopower in minimum achieves the giant value ~ 85% in magnetic field 14.17 kOe. It is shown that thermopower is largely caused by the presence of ferromagnetic nanoclusters of ferron-type and to a lesser degree of CE-type antiferromagnetic clusters, in which there is a charge ordering, displacing oxygen ions.

Partial Dissolution of Charge Order Phase Observed in -(BEDT-TTF)2PF6 Single Crystal Field Effect Transistor

2016 ◽  
Vol 16 (4) ◽  
pp. 3267-3272
Author(s):  
Masatoshi Sakai ◽  
Norifumi Moritoshi ◽  
Shigekazu Kuniyoshi ◽  
Hiroshi Yamauchi ◽  
Kazuhiro Kudo ◽  
...  
Keyword(s):  
Electric Field ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Crystal Field ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Electrical Conductance ◽  
Charge Order ◽  
Crystal Field Effect ◽  
Effect Transistor

The effect of an applied gate electric field on the charge-order phase in β-(BEDT-TTF)2PF6 single-crystal field-effect transistor structure was observed at around room temperature by technical improvement with respect to sample preparation and electrical measurements. A relatively slight but systematic increase of the electrical conductance induced by the applied gate electric field and its temperature dependence was observed at around the metal-insulator transition temperature (TMI). The temperature dependence of the modulated electrical conductance demonstrated that TMI was shifted toward the lower side by application of a gate electric field, which corresponds to partial dissolution of the charge-order phase. The thickness of the partially dissolved charge order region was estimated to be several score times larger than the charge accumulation region.

Ion Induced Damage and their Annealing in LiTaO3 Single Crystal

1995 ◽  
Vol 396 ◽  
Author(s):  
Z Zhang ◽  
I.A. Rusakova ◽  
W.K. Chu
Keyword(s):  
Curie Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Thermal Annealing ◽  
Crystalline Structure ◽  
Room Temperature ◽  
Complete Recovery ◽  
Oxygen Ions ◽  
Annealing Temperatures ◽  
Crystal Interface

AbstractLiTaO3 single crystals have been implanted with 100 keV oxygen ions at room temperature with doses of 1×1014 /cm2,6xl014/cm2,1.2x1015/cm2, 6xl015/cm2, and 2xl016/cm2. Annealing temperatures ranged from 550 °C to 1075 °C. RBS-channeling and TEM were used for characterization. For partially damaged samples, complete recovery of the crystalline structure was achieved after annealing at 550 °C, which is below the Curie temperature. For totally amorphized samples, thermal annealing induced multidomain growth. These domains extend beyond the original amorphous/crystal interface deep into bulk (1 – 1.5 μm ).

scholarly journals Connection of thermopower, magnetothermopower with resistivity and magnetoresistance in manganites with Nd and Sm

2018 ◽  
Vol 185 ◽  
pp. 06014 ◽  
Author(s):  
Luidmila Koroleva ◽  
Ivan Batashev ◽  
Artem Morozov ◽  
Anatolii Balbashov ◽  
Henryk Szymczak ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Single Crystal ◽  
Temperature Interval ◽  
Impurity States ◽  
Wide Temperature Interval ◽  
Concentration Of Impurities

Thermopower, magnetothermopower resistivity and magnetoresistance of single crystal samples Re(1-x)SrxMnO3 (0 ≤ x ≤ 0.3, Re = Nd, Sm) were studied in wide temperature interval, included the Curie temperature TC. Giant maxima of resistivity and thermopower, very big negative magnetothermopower and magnetoresistance were found in TC region. So, a giant maximum of thermopower in TC was found, which suppressed by magnetic field. Simultaneous magnetic field destroys magneto-impurity states – ferrons as evidenced the maxima resistivity and magnetoresistance in TC Hence it follows that giant thermopower in manganites are produced by ferrons and its value is set by the quantity of impurities, that is the concentration of impurities and the volume of sample.

A COMPARISON OF RESISTANCE BROADENING IN MAGNETIC FIELD OF SINGLE CRYSTAL YBa2Cu3O7−δ AND THE ORGANIC SUPERCONDUCTOR κ-(BEDT-TTF)2Cu[N(CN)2]Br

1991 ◽  
Vol 05 (08) ◽  
pp. 547-554 ◽  
Author(s):  
W.K. KWOK
Keyword(s):  
Magnetic Field ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Applied Magnetic Field ◽  
Organic Superconductor ◽  
High Magnetic Fields ◽  
Resistive Transition ◽  
Resistivity Measurements ◽  
Zero Resistance

AC resistivity measurements in fields up to 8 Tesla in fully oxygenated and oxygen deficient single crystals of YBa 2 Cu 3 O 7−δ are presented. Fully oxygenated crystals show the characteristic ‘fantail’ broadening in magnetic field where the onset temperature remains virtually independent of the applied magnetic field and the zero resistance temperature decreases dramatically. However, in oxygen deficient crystals, the temperature dependence of the resistivity undergoes a change in shape at high magnetic fields. These results are compared with the recently discovered highest Tc=11.6 K organic superconductor κ- (ET) 2 Cu[N(CN) 2] Br where the shape of the resistive transition for H||b undergoes a change from a ‘fantail’ resistive broadening in magnetic field to that of a more conventional low Tc superconductor.

Magnetic and Dielectric Properties of PbFeBO4 and PbMnBO4 Single Crystals

2014 ◽  
Vol 215 ◽  
pp. 372-377 ◽  
Author(s):  
A.I. Pankrats ◽  
K.A. Sablina ◽  
D.A. Velikanov ◽  
O.A. Bayukov ◽  
A.M. Vorotynov ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Curie Temperature ◽  
Single Crystal ◽  
Single Crystals ◽  
Neel Temperature ◽  
Strong Anisotropy ◽  
Néel Temperature ◽  
X Ray ◽  
Magnetic And Dielectric Properties ◽  
Magnetic Dielectric

PbFeBO4 and PbMnBO4 single crystals were synthesized. The X-ray, magnetic, dielectric, Mössbauer, and resonance investigations of the crystals were fulfilled. It is established that single-crystal PbFeBO4 is an antiferromagnet with a Néel temperature TN =114 K, while PbMnBO4 is a ferromagnet with a Curie temperature TC = 31 K. Both single-crystal compounds have a strong anisotropy of the magnetic and dielectric properties.

Messung der Magnetfelder am Kernort von 152 Sm und 154 Sm im Sm6Mn23 mit Hilfe der Spinpräzessionsmethode / Measurement of the local magnetic field, at the site of Sm in Sm6Mn23 by the spin precession method

1971 ◽  
Vol 26 (10) ◽  
pp. 1563-1566
Author(s):  
F. W. Richter ◽  
J. Schütt
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Temperature Dependence ◽  
Angular Correlation ◽  
Perturbed Angular Correlation ◽  
Coulomb Excitation ◽  
Correlation Method ◽  
Spin Precession ◽  
Local Magnetic Field ◽  
The Magnetic Field

Abstract The magnetic field at the site of the nuclei 152 Sm and 154 Sm in a ferrimagnetic Sm6Mn23 probe has been measured by means of the perturbed angular correlation method after Coulomb excitation. The temperature dependence of the magnetic field has been investigated and compared with the results of macroscopic experiments. It can be concluded from the present work that the magnetic field Heff(T) at the site of the Sm nuclei is proportional to the macroscopic magnetisation J (T). We obtained a ferrimagnetic Curie Temperature of TC = 438(5) K in good aggreement with macroscopic values and Heff (T=0 K) = 1300(50) kOe.

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