Giant 1/f Noise in Low-Tc CMR Manganites: Evidence of the Percolation Threshold

1999 ◽  
Vol 602 ◽  
Author(s):  
V. Podzorov ◽  
M. Uehara ◽  
M. E. Gershenson ◽  
T. Y. Koo ◽  
S-W. Cheong
Keyword(s):  
Phase Separation ◽  
Single Crystal ◽  
Percolation Threshold ◽  
Single Crystals ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Percolation Network

AbstractWe observed a dramatic peak in the 1/f noise at the metal-insulator transition (MIT) in low-Tc, manganites. This many-orders-of-magnitude noise enhancement is observed for both polycrystalline and single-crystal samples of La5/8−y. Pry, Ca3/8MnO3 (y = 0.35 – 0.4) and Pr1−xCaxMnO3 (x = 0.35 – 0.5). This observation strongly suggests that the microscopic phase separation in the low-Tc, manganites causes formation of a percolation network, and that the observed MIT is a percolation threshold. It is shown that the scale of phase separation in polycrystalline samples is much smaller than that in single crystals.

scholarly journals Surface Metal-Insulator Transition on a Vanadium Pentoxide (001) Single Crystal

2007 ◽  
Vol 99 (22) ◽  
Author(s):  
R.-P Blum ◽  
H. Niehus ◽  
C. Hucho ◽  
R. Fortrie ◽  
M. V. Ganduglia-Pirovano ◽  
...  
Keyword(s):  
Single Crystal ◽  
Vanadium Pentoxide ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Surface Metal

scholarly journals Anisotropic Phase Separation through the Metal-Insulator Transition in Amorphous Alloys

1994 ◽  
Vol 73 (8) ◽  
pp. 1118-1121 ◽  
Author(s):  
Michael J. Regan ◽  
Marybeth Rice ◽  
Marcela B. Fernandez van Raap ◽  
Arthur Bienenstock
Keyword(s):  
Phase Separation ◽  
Amorphous Alloys ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Anisotropic Phase

Effect of uniaxial pressure on metal-insulator transition in (Sm1−yNdy)0.52Sr0.48MnO3 single crystals

2009 ◽  
Vol 94 (25) ◽  
pp. 252506 ◽  
Author(s):  
A. Murugeswari ◽  
P. Sarkar ◽  
S. Arumugam ◽  
N. Manivannan ◽  
P. Mandal ◽  
...  
Keyword(s):  
Single Crystals ◽  
Insulator Transition ◽  
Uniaxial Pressure ◽  
Metal Insulator Transition ◽  
Metal Insulator

METAL–INSULATOR TRANSITION AND THE TEMPERATURE OF THE PSEUDOGAP ANOMALY OPENING IN PRASEODYMIUM DOPED Y1-zPrzBa2Cu3O7-δ SINGLE CRYSTALS

2013 ◽  
Vol 27 (04) ◽  
pp. 1350029 ◽  
Author(s):  
R. V. VOVK ◽  
Z. F. NAZYROV ◽  
I. L. GOULATIS ◽  
A. CHRONEOS ◽  
V. M. PINTO SIMOES
Keyword(s):  
Electrical Resistivity ◽  
Single Crystals ◽  
Insulator Transition ◽  
Critical Regime ◽  
Significant Shift ◽  
Asymptotic Dependence ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
The One ◽  
Praseodymium Doping

The influence of praseodymium doping on the electrical resistivity in the ab-plane of Y 1-z Pr z Ba 2 Cu 3 O 7-δ single crystals, is investigated. It is determined that as the concentration of praseodymium (0.0 ≤ z ≤ 0.5) is rising there occurs a significant shift of the temperature regions, corresponding to the metal–insulator transitions, as well as to the regime of the implementation of the pseudogap anomaly. The part of the curves related to the metal–insulator transition are well described by means of an asymptotic dependence that corresponds to the implementation of a quantum critical regime in the system, the so-called law of the "one third".

Magnetoelastic coupling in strained La0.7Ca0.3MnO3//BaTiO3 Thin Films

2013 ◽  
Vol 1587 ◽  
Author(s):  
A. Alberca ◽  
J. Azpeitia-Urkia ◽  
J. Tornos ◽  
C. Munuera ◽  
F. J. Mompean ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Separation ◽  
Curie Temperature ◽  
Insulator Transition ◽  
Strong Tendency ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Interfacial Effects ◽  
Magnetoelastic Coupling ◽  
Highly Strained

ABSTRACTIn this paper, we explore the interfacial effects appearing in highly strained La0.7Ca0.3MnO3 (LCMO) ultra-thin films (10-12nm) grown on BaTiO3 (BTO) ferroelectric substrates. The strong tendency to phase separation of this optimally doped manganite contributes to the exotic phenomena observed in magnetism and transport experiments: the so-called Matteucci magnetic loops, magnetic granularity and a second metal insulator transition are observed between 50K and the LCMO Curie temperature, 180K. All these properties define the multiferroic character of these heterostructures, which in LCMO//BTO system is strongly linked to magnetoelastic coupling.

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