Pressure-Induced Insulator-Metal Transition in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>LaMnO</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:math>: A Slave-Boson Approach

Fuhr, J. D.; Avignon, M.; Alascio, B.

doi:10.1103/physrevlett.100.216402

Cited by 25 publications

(31 citation statements)

References 11 publications

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“…Especially important is the transition to the insulating phase caused by the correlation effects associated with the electron-electron interaction [1]. In the metallic phase near the transition point it has been observed fluctuations and orderings in the spin, charge, and orbital degrees of freedom, properties which are frequently quite different from those of ordinary metals [2,3]. The insulator-to-metal transition could be driven by means of control of key parameters such as band filling or energy bandwidth.…”

Section: Introductionmentioning

confidence: 99%

Insulator-to-metal transition in vanadium supersaturated silicon: variable-range hopping and Kondo effect signatures

García-Hemme¹,

Montero²,

García-Hernansanz³

et al. 2016

J. Phys. D: Appl. Phys.

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We report the observation of the insulator-to-metal transition in crystalline silicon samples supersaturated with vanadium. Ion implantation followed by pulsed laser melting and rapid resolidification produce high quality single-crystalline silicon samples with vanadium concentrations that exceed equilibrium values in more than 5 orders of magnitude. Temperature-dependent analysis of the conductivity and Hall mobility values for temperatures from 10 K to 300 K indicate that a transition from an insulating to a metallic phase is obtained at a vanadium concentration between 1.1 × 10 20 and 1.3 × 10 21 cm −3 . Samples in the insulating phase present a variable-range hopping transport mechanism with a Coulomb gap at the Fermi energy level. Electron wavefunction localization length increases from 61 to 82 nm as the vanadium concentration increases in the films, supporting the theory of impurity band merging from delocalization of levels states. On the metallic phase, electronic transport present a dispersion mechanism related with the Kondo effect, suggesting the presence of local magnetic moments in the vanadium supersaturated silicon material.

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Section: Introductionmentioning

confidence: 99%

Insulator-to-metal transition in vanadium supersaturated silicon: variable-range hopping and Kondo effect signatures

García-Hemme¹,

Montero²,

García-Hernansanz³

et al. 2016

J. Phys. D: Appl. Phys.

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“…[1][2][3][4] As a result, there have been many experimental [5][6][7][8] and theoretical [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] studies of the end-member compound LaMnO 3 (LaMnO 3 ). The observed sequence of phases with decreasing temperature is as follows: 8,26 At very high temperature (above 1010 K), LaMnO 3 has a rhombohedral R3c structure, produced by rotation of the oxygen octahedron network of the ideal perovskite structure.…”

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confidence: 99%

Strong coupling of Jahn-Teller distortion to oxygen-octahedron rotation and functional properties in epitaxially strained orthorhombic LaMnO3

et al. 2013

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First-principles calculations reveal a large cooperative coupling of Jahn-Teller (JT) distortion to oxygenoctahedron rotations in perovskite LaMnO 3 . The combination of the two distortions is responsible for stabilizing the strongly orthorhombic A-AFM insulating (I ) eP bnm ground state relative to a metallic ferromagnetic (FM-M) phase. However, epitaxial strain due to coherent matching to a crystalline substrate can change the relative stability of the two states. In particular, coherent matching to a square-lattice substrate favors the less orthorhombic FM-M phase, with the A-AFM phase stabilized at higher values of tensile epitaxial strain due to its larger volume per formula unit, resulting in a coupled magnetic and metal-insulator transition at a critical strain close to 1%. At the phase boundary, a very large magnetoresistance is expected. Tensile epitaxial strain enhances the JT distortion and opens the band gap in the A-AFM-I c-eP bnm phase, offering the opportunity for band-gap engineering. Compressive epitaxial strain induces a transition within the FM-M phase from the c-eP bnm orientation to the ab-eP bnm orientation with a change in the direction of the magnetic easy axis relative to the substrate, yielding strain-controlled magnetization at the phase boundary. Similar behavior is expected in other JT active P bnm perovskites. (La,M)MnO 3 (M = Ca, Pr, Sr, Ba) has been of great interest due to the couplings among structure, magnetic and orbital orderings, and the resulting functional properties, such as colossal magneto-resistance (CMR). 1-4 As a result, there have been many experimental 5-8 and theoretical 9-25 studies of the end-member compound LaMnO 3 (LaMnO 3 ). The observed sequence of phases with decreasing temperature is as follows: 8,26 At very high temperature (above 1010 K), LaMnO 3 has a rhombohedral R3c structure, produced by rotation of the oxygen octahedron network of the ideal perovskite structure. From 1010 K down to 750 K, it has an orthorhombic P bnm structure produced by a different pattern of octahedral rotations. At 750 K, an orbital-order transition occurs by a cooperative Jahn-Teller transition; 27 however, this distortion does not break the symmetry of the P bnm structure. Finally, a magnetic transition to an A-type antiferromagnetic (A-AFM) ordering (ferromagnetic alignment in the xy planes, with spin direction alternating from plane to plane) occurs at 135 K.It proves to be challenging to reproduce the observed A-AFM ground state of LaMnO 3 , with its half filled e g level, from first principles. If the structural parameters are fixed to the experimental values, the correct magnetic ordering is obtained with a range of density-functional-theory (DFT) methods. However, full optimization of the structure within DFT generally gives a competing FM-M phase as the ground state, 11,17 and the correct ground state is obtained only in calculations with both a generalized gradient form of the density functional and inclusion of a Hubbard U . 16 More generally, various couplings in com...

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“…A notable exception is the study of the crystal structure, Jahn-Teller distortion, orbital order, and pressureinduced insulator-metallic phase transition in LaMnO 3 , although the driving mechanism still remains controversial. [2][3][4][5][6][7][8] According to the pioneer work by Loa et al 2 , the Jahn-Teller effect and the concomitant orbital ordering are suppressed above 18 GPa. The system retains insulator behavior up to 32 GPa, undergoing a bandwidth driven insulator-metal phase transition.…”

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confidence: 99%

Structural and insulator-to-metal phase transition at 50 GPa in GdMnO3

et al. 2012

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We present a study of the effect of very high pressure on the orthorhombic perovskite GdMnO 3 by Raman spectroscopy and synchrotron x-ray diffraction up to 53.2 GPa. The experimental results yield a structural and insulator-to-metal phase transition close to 50 GPa, from an orthorhombic to a metrically cubic structure. The phase transition is of first order with a pressure hysteresis of about 6 GPa. The observed behavior under very high pressure might well be a general feature in rare-earth manganites. DOI:PACS:Rare-earth manganites have attracted a continuous attention for their complex correlation between lattice, electric and magnetic degrees of freedom.More recently, magnetoelectric and multiferroic properties of manganites have attracted a particular interest. 1 Most manganites crystallize at ambient conditions in a Pnma structure, which presents distortions away from the ideal cubic perovskite structure through cooperative Jahn-Teller distortion and tilt of the MnO 6 octahedra. Such manganites have been extensively studied as a function of temperature, magnetic field, strain (in thin films), or chemical composition. High pressure is another parameter allowing tuning different degrees of freedom in manganites, but remains little explored to date. A notable exception is the study of the crystal structure, Jahn-Teller distortion, orbital order, and pressureinduced insulator-metallic phase transition in LaMnO 3 , although the driving mechanism still remains controversial. [2][3][4][5][6][7][8] According to the pioneer work by Loa et al 2 , the Jahn-Teller effect and the concomitant orbital ordering are suppressed above 18 GPa. The system retains insulator behavior up to 32 GPa, undergoing a bandwidth driven insulator-metal phase transition. Other authors have reported the persistence of the Jahn-Teller distortion over the entire stability range of the insulating phase of LaMnO 3 , suggesting a non classical Mott insulator. 3,6 No other orthorhombic manganite has attracted such an attention, although we note the pressure investigation of structural properties of the magnetoelectric manganites TbMnO 3 and DyMnO 3 or BiMnO 3 , or more complex solid solutions. [9][10][11] To the best of our knowledge, manganites have not yet been investigated in the very high-pressure regime around 50 GPa, despite promising studies on similar orthoferrites or BiFeO 3 , which have revealed intriguing insulator-to-metal or structural transitions in a similar pressure range. [12][13][14][15] The aim of this work is to explore the effect of very high-pressure on rare-earth manganites. We have chosen GdMnO 3 which currently attracts a considerable attention as a frustrated magnetic system for which a ferroelectric order can be induced by application of a modest magnetic field. [16][17][18] Its phase diagram has been extensively studied as a function of external parameters: Temperature, doping, and high magnetic fields. 16,18,19 Pressure has only been explored up to 1 GPa through a pressure-dependent study of the dielectric constant at ...

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Pressure-Induced Insulator-Metal Transition inLaMnO3: A Slave-Boson Approach

Cited by 25 publications

References 11 publications

Insulator-to-metal transition in vanadium supersaturated silicon: variable-range hopping and Kondo effect signatures

Insulator-to-metal transition in vanadium supersaturated silicon: variable-range hopping and Kondo effect signatures

Strong coupling of Jahn-Teller distortion to oxygen-octahedron rotation and functional properties in epitaxially strained orthorhombic LaMnO3

Structural and insulator-to-metal phase transition at 50 GPa in GdMnO3

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