Magnetotransport in Thin Films of Lan-nxCa1+nxMnnO3n+1 (n=2,3, and ∞)

1997 ◽  
Vol 494 ◽  
Author(s):  
H. Asano ◽  
J. Hayakawa ◽  
M. Matsui
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Spin Fluctuation ◽  
Two Dimensional ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Number Of Layers ◽  
The Difference

ABSTRACTWith a use of the epitaxial a-axis thin films of perovskite series Lan-nxCa1+nxMnnO3n+1 (n=2,3, and ∞) with fixed carrier concentration (x=0.3), the transport properties of the series compounds have been examined to be associated with the difference in the number of the MnO2 layers. Results have indicated that a reduction in the number of layers results in systematic changes in the various features. These include an increase in resistivity, a decrease in resistivity peak temperature Tcρ corresponding to the metal-insulator transition, an enhancement of the maximum MR near Tcρ, and an increase in low temperature intrinsic MR. In order to explain the variation in these features with the number of MnO2 layers, it is necessary to take both anisotropie c-axis transfer interaction and two-dimensional spin fluctuation into account.

Transport properties of two-dimensional hole gas in a Ge1−x Si x /Ge/Ge1−x Si x quantum well in the vicinity of metal-insulator transition

2007 ◽  
Vol 41 (11) ◽  
pp. 1315-1322 ◽  
Author(s):  
Yu. G. Arapov ◽  
V. N. Neverov ◽  
G. I. Harus ◽  
N. G. Shelushinina ◽  
M. V. Yakunin ◽  
...  
Keyword(s):  
Quantum Well ◽  
Transport Properties ◽  
Insulator Transition ◽  
Two Dimensional ◽  
Metal Insulator Transition ◽  
Metal Insulator

TRANSPORT PROPERTIES OF Ag-DOPED La0.7Ca0.3MnO3 THIN FILMS ON SILICON SUBSTRATE

2010 ◽  
Vol 24 (27) ◽  
pp. 5451-5456 ◽  
Author(s):  
H. C. JIANG ◽  
W. L. ZHANG ◽  
X. F. CAO ◽  
W. X. ZHANG ◽  
B. PENG
Keyword(s):  
Thin Films ◽  
Transition Temperature ◽  
Transport Properties ◽  
Silicon Substrate ◽  
Annealing Temperature ◽  
Rf Magnetron Sputtering ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Higher Temperature

Ag -doped La 0.7 Ca 0.3 MnO 3 (LCMO) films were prepared on silicon substrate by RF magnetron sputtering. The dependences of transport properties on annealing temperature were explored. It is shown that the resistivity of the samples decreases and the metal–insulator transition temperature shifts to higher temperature with the increase in annealing temperature. Two metal–insulator transition temperatures are presented in the R – T plots of Ag -doped LCMO films, which can be explained by the Ag 1+ substitution of La 3+ to form La 1-x Ag x MnO 3 compound. Compared with LCMO thin films, Ag -doping can observably improve the TM-I and decrease the resistivity of the samples.

The Influence of Local Magnetization on Transport in Cd0.91Mn0.09Te:In

1992 ◽  
Vol 290 ◽  
Author(s):  
S. Von Molnar ◽  
T. Penney ◽  
I. Terry ◽  
P. Becla
Keyword(s):  
Transport Properties ◽  
Carrier Concentration ◽  
Magnetic Semiconductors ◽  
Localization Length ◽  
Insulator Transition ◽  
Local Magnetization ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Magnetic Polarons ◽  
Transport Effect

AbstractWe describe the influence of local magnetization on electron localization and transport properties on the insulating side of the metal insulator transition in the dilute magnetic persistent photoconductor Cd0.091 Mn0.09Te:ln. Measurements of both the temperature dependence of the transport properties, and also the dielectric constant, are reported for just one sample in which the carrier concentration n was varied by photodoping. From these results we are able to extract the carrier concentration dependence of the localization length and the permitivity of the electrons. We also report onl a new transport effect which occurs at ultra low temperatures and/or carrier concentrations very close to the metal insulator transition. We find that this mechanism is totally magnetic in origin and are able to explain it in terms of the well devewloped ideas of magnetic polarons in magnetic semiconductors.

scholarly journals Phase transition in vanadium oxide films formed by multistep deposition

2021 ◽  
Vol 24 (04) ◽  
pp. 362-371
Author(s):  
V.P. Kladko ◽  
◽  
V.P. Melnik ◽  
О.I. Liubchenko ◽  
B.M. Romanyuk ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Low Temperature ◽  
Vanadium Oxide ◽  
Multistep Method ◽  
Metal Insulator Transition ◽  
Two Stage ◽  
Metal Insulator ◽  
Low Temperature Annealing ◽  
Temperature Deposition

VOx films deposited using the multistep method have been investigated. These films were deposited by repeating the two-stage method of low-temperature deposition – low-temperature annealing. The structure and characteristics of VOx thin films have been studied. Taking into account the obtained results, theoretical modeling of the structure was performed and the parameters of the metal-insulator transition have been calculated.

Preparation and Properties of (La, Sr) MnO3 Thin Films Prepared by Sol-Gel Method

2007 ◽  
Vol 336-338 ◽  
pp. 220-223 ◽  
Author(s):  
Kuo Jiang ◽  
X.Y. Bao ◽  
Sheng Kai Gong
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Sol Gel ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Uniform Microstructure ◽  
Sol Gel Process ◽  
Metallic Conduction

LSMO films with various thicknesses were prepared on single crystal Si (111) substrates by sol-gel process. The films were dense and had a uniform microstructure. The films showed metallic conduction characteristics at low temperature and insulator characteristics at high temperature. The metal-insulator transition temperatures (Tmi) of the films were remarkably lower than that of the bulk ceramics. The effect is related to the distortion of crystal lattice resulted from the residual stress in the films.

Emergence of size induced metallic state in the ferromagnetic insulating Pr0.8Sr0.2MnO3 manganite: Breaking of surface polarons

2015 ◽  
Vol 8 (2) ◽  
pp. 2084-2093 ◽  
Author(s):  
PROLOY TARAN DAS ◽  
Arun Kumar Nigam ◽  
Tapan Kumar Nath
Keyword(s):  
Transport Properties ◽  
Metallic State ◽  
Temperature Dependent ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
System A ◽  
Surface Disorder ◽  
Bulk System ◽  
Magnetic Transport ◽  
Grain Surface

Nano-dimensional effects on electronic-, magneto-transport properties of granular ferromagnetic insulating (FMI) Pr0.8Sr0.2MnO3 (PSMO) manganite (down to 40 nm) have been investigated in details. From the electronic and magnetic transport properties, a metallic state has been observed in grain size modulation by suppressing the ferromagnetic insulating state of PSMO bulk system. A distinct metal-insulator transition (MIT) temperature around 150 K has been observed in all nanometric samples. The observed insulator to metallic transition with size reduction can be explained with surface polaron breaking model, originates due to enhanced grain surface disorder. This proposed phenomenological polaronic model plays a significant role to understand the polaronic destabilization process on the grain surface regime of these phase separated nano-mangnatie systems. Temperature dependent resistivity and magnetoresistance data in presence of external magnetic fields are investigated in details with various compatible models.

Crystal growth and metal-insulator transition in two-dimensional layered rare-earth palladates

2018 ◽  
Vol 2 (8) ◽  
Author(s):  
Yoshiko Nanao ◽  
Yoshiharu Krockenberger ◽  
Ai Ikeda ◽  
Yoshitaka Taniyasu ◽  
Michio Naito ◽  
...  
Keyword(s):  
Rare Earth ◽  
Crystal Growth ◽  
Insulator Transition ◽  
Two Dimensional ◽  
Metal Insulator Transition ◽  
Metal Insulator

EFFECT OF DISORDER ON THE ELECTRICAL PROPERTIES OF AMORPHOUS CONDUCTING CARBON FILMS: OBSERVANCE OF FIELD INDUCED METAL-INSULATOR TRANSITION?

2000 ◽  
Vol 14 (02n03) ◽  
pp. 224-229 ◽  
Author(s):  
V. MEENAKSHI ◽  
S. V. SUBRAMANYAM
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Carbon Films ◽  
Electronic Systems ◽  
Metal Insulator Transition ◽  
Preparation Temperature ◽  
Metal Insulator ◽  
Effect Of Disorder

In this work, the influence of disorder on the electrical properties (DC conductivity and Magnetoresistance) of amorphous conducting carbon films, prepared by the pyrolysis of Tetra chloro phthalic anhydride, is reported and discussed. The low temperature electrical properties are analyzed in terms of the various models developed for disordered electronic systems. The results indicate the possibility of a metal - insulator (M-I) transition, both as a function of preparation temperature and an external magnetic field.

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