Model for strain-induced metal-insulator phase coexistence in colossal magnetoresistive perovskite manganites (invited)

2006 ◽  
Vol 99 (8) ◽  
pp. 08A703 ◽  
Author(s):  
K. H. Ahn ◽  
T. Lookman ◽  
A. R. Bishop
Keyword(s):  
Phase Coexistence ◽  
Perovskite Manganites ◽  
Metal Insulator ◽  
Colossal Magnetoresistive

Strain-induced metal–insulator phase coexistence in perovskite manganites

Nature ◽  
2004 ◽  
Vol 428 (6981) ◽  
pp. 401-404 ◽  
Author(s):  
K. H. Ahn ◽  
T. Lookman ◽  
A. R. Bishop
Keyword(s):  
Phase Coexistence ◽  
Perovskite Manganites ◽  
Metal Insulator

scholarly journals Nanoscale phase coexistence at the metal-insulator transition in Cu(Ir1–xCrx)2S4

2014 ◽  
Vol 70 (a1) ◽  
pp. C1351-C1351
Author(s):  
Emil Bozin ◽  
Kevin Knox ◽  
Pavol Juhas ◽  
Yew San Hor ◽  
John Mitchell ◽  
...  
Keyword(s):  
Phase Diagram ◽  
High Temperature Superconductors ◽  
Phase Coexistence ◽  
Metal Insulator ◽  
X Ray ◽  
Colossal Magnetoresistive ◽  
Atomic Pair Distribution Function ◽  
X Ray Scattering ◽  
Atomic Pair ◽  
Emergent Behaviors

Increasingly, nanoscale phase coexistence and hidden broken symmetry states are being found in the vicinity of metal-insulator transitions (MIT), for example, in high temperature superconductors, heavy fermion and colossal magnetoresistive materials, but their importance and possible role in the MIT and related emergent behaviors is not understood. Despite their ubiquity, they are hard to study because they produce weak diffuse signals in most measurements. Here we propose Cu(Ir1–xCrx)2S4 as a model system for studying nanoscale phase coexistence at the MIT, where robust local structural signals lead to key new insights. We demonstrate by x-ray scattering measurements and atomic pair distribution function approach a hitherto unobserved coexistence of a Ir4+ charge-localized dimer phase and Cr-ferromagnetism. The resulting phase diagram that takes into account the short range dimer order, is highly reminiscent of a generic MIT phase diagram similar to the cuprates. The results represent the first observation of nanoscale phase coexistence in iridates [1]. We suggest that the presence of quenched strain from dopant ions acts as an arbiter deciding between the competing ground states.

Strain-induced crossover of the metal-insulator transition in perovskite manganites

2005 ◽  
Vol 71 (6) ◽  
Author(s):  
Y. Ogimoto ◽  
M. Nakamura ◽  
N. Takubo ◽  
H. Tamaru ◽  
M. Izumi ◽  
...  
Keyword(s):  
Insulator Transition ◽  
Perovskite Manganites ◽  
Metal Insulator Transition ◽  
Metal Insulator

Metal–insulator transition induced by oxygen isotope exchange in the magnetoresistive perovskite manganites

Nature ◽  
10.1038/34380 ◽  
1998 ◽  
Vol 391 (6663) ◽  
pp. 159-161 ◽  
Author(s):  
N. A. Babushkina ◽  
L. M. Belova ◽  
O. Yu. Gorbenko ◽  
A. R. Kaul ◽  
A. A. Bosak ◽  
...  
Keyword(s):  
Oxygen Isotope ◽  
Isotope Exchange ◽  
Insulator Transition ◽  
Perovskite Manganites ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Oxygen Isotope Exchange

scholarly journals Crossover of angular dependent magnetoresistance with the metal-insulator transition in colossal magnetoresistive manganite films

2009 ◽  
Vol 95 (13) ◽  
pp. 132506 ◽  
Author(s):  
Y. Z. Chen ◽  
J. R. Sun ◽  
T. Y. Zhao ◽  
J. Wang ◽  
Z. H. Wang ◽  
...  
Keyword(s):  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Colossal Magnetoresistive

Magnetic dynamics in colossal magnetoresistive perovskite manganites

1998 ◽  
Vol 356 (1742) ◽  
pp. 1563-1575 ◽  
Author(s):  
T. G. Perring ◽  
G. Aeppli ◽  
S. M. Hayden ◽  
Y. Tokura ◽  
Y. Moritomo ◽  
...  
Keyword(s):  
Perovskite Manganites ◽  
Magnetic Dynamics ◽  
Colossal Magnetoresistive

POLARON ORDERING IN FERROMAGNETIC COLOSSAL MAGNETORESISTIVE OXIDES

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3711-3718 ◽  
Author(s):  
L. VASILIU-DOLOC ◽  
R. OSBORN ◽  
S. ROSENKRANZ ◽  
J. MESOT ◽  
J. F. MITCHELL ◽  
...  
Keyword(s):  
Low Temperature ◽  
Neutron Scattering ◽  
Wave Vector ◽  
Diffuse Scattering ◽  
Short Range ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Charge Delocalization ◽  
X Ray ◽  
Colossal Magnetoresistive

We review our recent x-ray and neutron scattering studies that reveal static diffuse scattering due to polarons in the paramagnetic phase of the colossal magnetoresistive manganites La 2-2x Sr 1+2x Mn 2 O 7, with x=0.40 and 0.44. We show that the polarons exhibit short-range incommensurate correlations that grow with decreasing temperature, but disappear abruptly at the combined ferromagnetic and metal-insulator transition in the x=0.40 system because of the sudden charge delocalization, while persisting at low temperature in the antiferromagnetic x=0.44 system. The "melting" of the polaron ordering as we cool through TC occurs with the collapse of the polaron scattering itself in the x=0.40 system. The polaron order is characterized by an ordering wave vector q=(0.3,0,1) that is almost independent of x for x≥0.40, and is consistent with a model of disordered stripes.

scholarly journals Spin wave damping arising from phase coexistence below Tc in colossal magnetoresistive La0.7Ca0.3MnO3

2017 ◽  
Vol 96 (10) ◽  
Author(s):  
Joel S. Helton ◽  
Susumu K. Jones ◽  
Daniel Parshall ◽  
Matthew B. Stone ◽  
Dmitry A. Shulyatev ◽  
...  
Keyword(s):  
Spin Wave ◽  
Phase Coexistence ◽  
Wave Damping ◽  
Colossal Magnetoresistive

scholarly journals Structural and Magnetic States in Layered Manganites: An Expanding View of the Phase Diagram

1999 ◽  
Vol 602 ◽  
Author(s):  
J.F. Mitchell ◽  
J.E. Millburn ◽  
C. Ling ◽  
D.N. Argyriou ◽  
H. N. Bordallo
Keyword(s):  
Degrees Of Freedom ◽  
Hole Concentration ◽  
Charge Ordering ◽  
Perovskite Manganites ◽  
Electronic Interactions ◽  
Colossal Magnetoresistive ◽  
Reduced Dimensions ◽  
Incommensurate Magnetic Structure ◽  
Extreme Sensitivity ◽  
Magnetic States

AbstractColossal magnetoresistive (CMR) manganites display a spectacular range of structural, magnetic, and electronic phases as a function of hole concentration, temperature, magnetic field, etc. Although the bulk of research has concentrated on the 3-D perovskite manganites, the ability to study anisotropic magnetic and electronic interactions made available in reduced dimensions has accelerated interest in the layered Ruddlesden-Popper (R-P) phases of the manganite class. The quest for understanding the coupling among lattice, spin, and electronic degrees of freedom (and dimensionality) is driven by the availability of high quality materials. In this talk, we will present recent results on synthesis and magnetic properties of layered manganites from the La2−2xSr1+2xMn2O7 series in the Mn4+-rich regime x > 0.5. This region of the composition diagram is populated by antiferromagnetic structures that evolve from the A-type layered order to G-type “rocksalt” order as x increases. Between these two regimes is a wide region (0.7 < x < 0.9) where an incommensurate magnetic structure is observed. The IC structure joins spin canting and phase separation as a mode for mixed-valent manganites to accommodate FM/AF competition. Transport in these materials is dominated by highly insulating behavior, although a region close to x = 0.5 exhibits metal-nonmetal transitions and an extreme sensitivity to oxygen content. We suggest two possible explanations for this transport behavior at doping just above x=0.5: localization by oxygen defects or charge ordering of Mn3+/Mn4+ sites.

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