HIGH-FIELD TRANSPORT PROPERTIES OF T'-Ln2-xCexCuO4 (Ln=Nd, Pr, La)

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3216-3219 ◽  
Author(s):  
T. SEKITANI ◽  
N. MIURA ◽  
M. NAITO
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Magnetic Fields ◽  
Transport Properties ◽  
Normal State ◽  
Low Temperatures ◽  
High Field ◽  
Magnetic Moments ◽  
Negative Magnetoresistance ◽  
High Magnetic Fields

We report low-temperature magnetotransport in the normal state of the electron-doped superconductors, Nd 2-x Ce x CuO 4, Pr 2-x Ce x CuO 4, and La 2-x Ce x CuO 4, by suppressing the superconductivity with high magnetic fields. The normal state ρ-T curve shows an up-turn at low temperatures, which has a log T dependence with saturation at lowest temperatures. The up-turn is gradually suppressed with increasing magnetic field, resulting in negative magnetoresistance. We discuss these findings on the basis of the Kondo scattering originating from the magnetic moments of Cu 2+ ions.

scholarly journals High-field Study of Layered Manganites R1/2Sr3/2MnO4 (R = La and Nd)

1999 ◽  
Vol 52 (2) ◽  
pp. 227
Author(s):  
M. Tokunaga ◽  
N. Miura ◽  
Y. Moritomo
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Study ◽  
Transport Properties ◽  
Low Temperatures ◽  
High Field ◽  
Colossal Magnetoresistance ◽  
Real Space ◽  
Charge Ordering ◽  
Pulsed Magnetic Fields

We have studied the effects of a magnetic field on the magnetism and transport properties of the layered manganites R1/2Sr3/2MnO4 (R = La and Nd) in pulsed magnetic fields up to 40 T. The R = La crystal shows metamagnetic-like transitions above 30 T, concomitantly with a colossal magnetoresistance (CMR) effect as large as [ρ(0) - ρ(H)]/ρ(H) > 103 with a field of µοH = 38 T at low temperatures. These transitions can be ascribed to the field-induced melting of the real-space ordering of the eg electrons (charge ordering). For the R = Nd crystal, a magnetic field along the c-axis enhances the two-dimensionality in the conductivity. Moreover, we observed metamagnetic-like transitions accompanied by the CMR effects at low temperatures, in spite of the absence of charge ordering.

LOW-TEMPERATURE NORMAL-STATE HALL EFFECT IN HIGH-TcBi2Sr2-xLaxCuO6+δ REVEALED BY 60 T MAGNETIC FIELDS

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3171-3174
Author(s):  
F. F. BALAKIREV ◽  
J. B. BETTS ◽  
G. S. BOEBINGER ◽  
S. ONO ◽  
Y. ANDO ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Carrier Concentration ◽  
Hall Coefficient ◽  
Normal State ◽  
Ground State ◽  
Low Temperatures ◽  
Optimal Doping ◽  
Underdoped Sample ◽  
Additional Support

We report low-temperature Hall coefficient in the normal state of the high-Tc superconductor Bi 2 Sr 2-x La x CuO 6+δ. The Hall coefficient was measured down to 0.5 K by suppressing superconductivity with a 60 T pulsed magnetic field. The carrier concentration was varied from overdoped to underdoped regimes by partially substituting Sr with La in a set of five samples. The observed saturation of the Hall coefficient at low temperatures suggests the ability to extract the carrier concentration of each sample. The most underdoped sample exhibits a diverging Hall coefficient at low temperatures, consistent with a depletion of carriers in the insulating ground state. The Hall number exhibits a sharp peak providing additional support for the existence of a phase boundary at the optimal doping.

TUNING OF THE MAGNETIC FIELD INDUCED SHARP BAND-EDGE OPTICAL ABSORPTION IN EUROPIUM CHALCOGENIDES

2004 ◽  
Vol 18 (27n29) ◽  
pp. 3813-3816 ◽  
Author(s):  
A. B. HENRIQUES ◽  
L. K. HANAMOTO ◽  
E. TER HAAR ◽  
E. ABRAMOF ◽  
A. Y. UETA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Optical Absorption ◽  
Low Temperatures ◽  
Optical Transition ◽  
Band Edge ◽  
Near Band Edge ◽  
High Magnetic Fields ◽  
Sharp Band ◽  
The Magnetic Field

The near band-edge polarized optical optical absortion spectra of EuTe at low temperatures and high magnetic fields were investigated. The samples were grown by MBE on BaF 2 substrates, and the thickness varied in the 0.18-2.0 μm range. At high magnetic fields, the well-known 4f7→4f65d(t2g) optical transition splits into two well resolved lines at σ+ and two lines for σ-. These lines can be described by localized transitions tunable by the d-f exchange interaction, with a quadratic dependence on the intensity of the external magnetic field. Comparative measurements of the magnetization and the optical absorption as a function temperature provides a further test of the model of a localized excitation extending over a few lattice sites.

STRUCTURAL AND MAGNETIC FIELD DEPENDENT TRANSPORT PROPERTIES OF p-MnxGe1-x/n-Ge HETEROJUNCTION

2009 ◽  
Vol 23 (17) ◽  
pp. 3579-3585
Author(s):  
SANDIP MAJUMDAR ◽  
AMAL KUMAR DAS ◽  
SAMIT KUMAR RAY
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Transport Properties ◽  
Low Temperatures ◽  
Impurity Band ◽  
Heterojunction Diode ◽  
Field Dependent ◽  
Current Rectification ◽  
Dependent Transport ◽  
Mn Doped

We report the study of a promising Ge -based magnetic heterojunction diode composed of a Mn -doped p - Ge film grown on lightly doped n - Ge film. Magnetic field dependent current rectification of the diode occurs at a low temperature. The measurements of resistivity and magnetoresistance in plane at low temperatures reveal the presence of impurity band in Ge due to Mn doping.

Energy behavior with magnetic field of negatively charged magnetoexcitons in quantum wells and heterojunctions

1999 ◽  
Vol 588 ◽  
Author(s):  
F. M. Munteanu ◽  
Y. Kim ◽  
C. H. Perry ◽  
D. G. Rickel ◽  
J. A. Simmons ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Quantum Well ◽  
Quantum Wells ◽  
Low Temperatures ◽  
High Magnetic Fields ◽  
Crossing Over ◽  
Sample Geometry ◽  
Energy Behavior

AbstractWe present the results of the magneto-photoluminescence measurements performed on modulation doped GaAs/AlGaAs heterostructures in high magnetic fields (up to 60T) and low temperatures (0.37−1.5K). With increasing magnetic field we observe the formation of the triplet and singlet states of negatively charged magneto-excitons (X−) in addition to the neutral exciton (X0). Their behavior with field strongly depends on the sample geometry. In the case of a modulation doped quantum well (QW) with a well-width of 200A, the and states cross at a magnetic field of about 40T, whereas for a modulation-doped single heterojunction (SHJ) these states show no crossing over the whole range of available fields.

Transport properties of CeNiSn at low temperatures and in high magnetic fields

1994 ◽  
Vol 199-200 ◽  
pp. 437-439 ◽  
Author(s):  
A. Hiess ◽  
C. Geibel ◽  
G. Sparn ◽  
C.D. Bredl ◽  
F. Steglich ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Transport Properties ◽  
Low Temperatures ◽  
High Magnetic Fields
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