Thickness-dependent magnetotransport in ultrathin manganite films

Sun, J. Z.; Abraham, David W.; Rao, R. A.; Eom, C. B.

doi:10.1063/1.124050

Cited by 374 publications

(274 citation statements)

References 11 publications

Supporting

Mentioning

255

Contrasting

Unclassified

Order By: Relevance

“…The LPCMO films were grown on NdGaO 3 , which is known to stabilize the pseudocubic structure of the FMM phase at low temperatures 19,20 . Hence, at the filmsubstrate interface a strain-stabilized FMM phase is formed at low temperatures.…”

Section: To Understand How Measurement Of C(t) Is More Than Just a Comentioning

confidence: 99%

“…At the resistance peaks the percolative IM transition for transport in the parallel direction through FMM domains occurs at We then justify this model by establishing two necessary and sufficient conditions to assure that R s can be ignored, namely: (1) the leakage resistance R 0 is significantly higher than any of the impedance elements in our configuration, and (2) Strain effects explain the occurrence of anisotropy and two separate percolation transitions. The LPCMO films were grown on NdGaO 3 , which is known to stabilize the pseudocubic structure of the FMM phase at low temperatures 19,20 . Hence, at the filmsubstrate interface a strain-stabilized FMM phase is formed at low temperatures.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Colossal magnetocapacitance and scale-invariant dielectric response in phase-separated manganites

et al. 2007

View full text Add to dashboard Cite

A full characterization of phase separation and the competition between phases is necessary for a comprehensive understanding of strongly-correlated electron materials (SCEM), such as under-doped high temperature superconductors 1,2 , complex oxide heterojunctions 3 , antiferromagnetic 4 and ferromagnetic 5 spinels, multiferroics 6,7 , rareearth ferroelectric manganites 8 , and mixed-valence manganites where phase competition is the dominant underlying mechanism governing the insulator-metal (IM) transition and the associated colossal magnetoresistance (CMR) effect [9][10][11] . Thin films of SCEMs are often grown epitaxially on planar substrates and typically have anisotropic properties that are usually not captured by edge-mounted four-terminal electrical measurements, which are primarily sensitive to in-plane conduction paths. Accordingly, the correlated interactions in the out-of-plane (perpendicular) direction cannot be measured but only inferred. We address this shortcoming and show here an experimental technique in which the SCEM under study, in our case a 600 Å-thick (La 1-y Pr y ) 0.67 Ca 0.33 MnO 3 (LPCMO) film, serves as the base electrode in a metal-insulator-metal (MIM) trilayer capacitor structure. This unconventional arrangement allows for simultaneous determination of colossal magnetoresistance (CMR) associated with dc transport parallel to the film substrate and colossal magnetocapacitance (CMC) associated with ac transport in the Page 2 of 32 perpendicular direction. We distinguish two distinct strain-related direction-dependent insulator-metal (IM) transitions and use Cole-Cole plots to establish a heretofore unobserved collapse of the dielectric response onto a universal scale-invariant power-law dependence over a large range of frequency, temperature and magnetic field. The resulting phase diagram defines an extended region where the competing interaction of the coexisting ferromagnetic metal (FMM) and charge-ordered insulator (COI) phases 10-15 has the same behavior over a wide range of temporal and spatial scales. At low frequency, corresponding to long length scales, the volume of the phase diagram collapses to a point defining the zero-field IM percolation transition in the perpendicular direction.The simultaneous measurement of the zero field (H = 0) parallel resistance R || (T) and perpendicular capacitance C(T) transport in the LPCMO film, which is embedded as the base electrode in the trilayer configuration shown schematically in Fig. 1a, is captured in the temperature-dependent curves of Fig. 1b. The two-terminal C(T) measurements correspond to the real part C′ (ω) of a complex lossy capacitance, C * (ω)= C′ (ω)−iC″ (ω), measured at f = ω/2π = 0.5 kHz. As temperature T decreases from 300K, the prevailing high temperature paramagnetic insulator (PI) phase gives way near T = 220 K 14 to a dominant COI phase having a resistance that rapidly increases as T continues to decrease. Minority phase FMM domains appear and begin to short circuit the resistance rise as T continues to decr...

show abstract

Section: To Understand How Measurement Of C(t) Is More Than Just a Comentioning

confidence: 99%

mentioning

confidence: 99%

Colossal magnetocapacitance and scale-invariant dielectric response in phase-separated manganites

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The CG is known to be sensitive to disorder [15]. In the present case disorder could arise due to the different impacts of the oxygen deficient and magnetically disordered dead layer in compressively strained (L47) and tensile strained (S47) films [16]. The higher values T f in films on LAO than that on the STO substrates could also be attributed to the slightly different nature of the CG state in the two set of films.…”

Section: Resultsmentioning

confidence: 77%

“…L47 (S47) shows saturation magnetization (M S )  466 emu/cm 3 (440 emu/cm 3 ) at a saturation field of H S  6 kOe (9 kOe), and remnant magnetization (M r )  258 emu/cm 3 (242 emu/cm 3 ), respectively. Generally, M ZFC (T)/M FC (T) divergence, the cusp-like behavior and the drop in ZFC magnetization at T<T P are regarded as signatures of metamagnetic state [16]. In the present case, the occurrence of (i) strong ZFC-FC divergence just below T C , (ii) temperature dependence of FC magnetization at T<T P , and (iii) shifting of the T P towards lower temperature in the FC curve, suggest that the magnetic state in the lower temperature regime is akin to cluster glass (CG) rather than spin glass (SG) [14,15].…”

Section: Resultsmentioning

confidence: 99%

Impact of substrate on magnetic phase coexistence in bicritical Sm0.53Sr0.47MnO3 thin films

Srivastava

Singh

Siwach

et al. 2012

Solid State Communications

View full text Add to dashboard Cite

Sm 0.53 Sr 0.47 MnO 3 thin films were deposited on single crystal LaAlO 3 (LAO/(001)) and SrTiO 3 (STO/(001)) substrates by DC magnetron sputtering. The -2 and -2 scans show that these films have very good crystallinity and the films on LAO and STO are under compressive and tensile strain, respectively. The films on LAO and STO substrates show ferromagnetic (insulator-metal) transition at T C~1 26 K (at T IM~1 28 K) and 120 K (T IM~1 17K), respectively.The magnetic state at T

show abstract

“…Complicating our understanding of the electronic properties of catalytically relevant complex oxide surfaces is the fact that at their surfaces and interfaces the broken translational symmetry fundamentally changes the properties 9,10 . While this has been shown to produce remarkable physics at interfaces [11][12][13] , at surfaces of three-dimensional (3D) perovskites the results are qualitatively different: many fully oxygenated 3D perovskite surfaces and interfaces exhibit a so-called nanoscale "dead layer" where the magnetic order and metal-insulator transitions that from the bulk are strongly reduced or even absent [14][15][16][17][18][19] . In first order, this can be explained by the decreased coordination at the surface that decreases the electronic band width, increases electronic correlations, and creates insulating phases.…”

mentioning

confidence: 99%

A persistent metal–insulator transition at the surface of an oxygen-deficient, epitaxial manganite film

et al. 2013

View full text Add to dashboard Cite

The oxygen stoichiometry has a large influence on the physical and chemical properties of complex oxides. Most of the functionality in e.g. catalysis and electrochemistry depends in particular on control of the oxygen stoichiometry. In order to understand the fundamental properties of intrinsic surfaces of oxygen-deficient complex oxides, we report on in situ temperature dependent scanning tunnelling spectroscopy experiments on pristine oxygen deficient, epitaxial manganite films. Although these films are insulating in subsequent ex situ in-plane electronic transport experiments at all temperatures, in situ scanning tunnelling spectroscopic data reveal that the surface of these films exhibits a metalinsulator transition (MIT) at 120 K, coincident with the onset of ferromagnetic ordering of small clusters in the bulk of the oxygen-deficient film. The surprising proximity of the surface MIT transition temperature of nonstoichiometric films with that of the fully oxygenated bulk suggests that the electronic properties in the surface region are not significantly affected by oxygen deficiency in the bulk. This carries important implications for the understanding and functional design of complex oxides and their interfaces with specific electronic properties for catalysis, oxide electronics and electrochemistry.In catalysis and electrochemistry the surface properties of catalyst and electrode materials dominate their functional performance. For oxide materials this is often associated with the bulk oxygen stoichiometry, with oxygen vacancies frequently improving the catalytic and electrochemical performance 1, 2 . This contrasts with the spectacular physical properties with promising functionality displayed by complex oxides such as perovskites [3][4][5][6] but that are generally strongly reduced or even eliminated by the introduction of oxygen vacancies 7 . Moreover, in nanoscale oxide heterostructures the possible large chemical and electrostatic potential gradients, and the high surface/volume ratios may drastically affect the properties of the material 8 . With respect to the chemically important surface properties, it is currently not clear whether an oxygen deficiency in the bulk of a three-dimensional (3D) perovskite affects these surface properties in concert with those of the bulk, or whether this is significantly different due to eg. altered oxygen vacancy formation energies near the surface due to different local ionic coordination or even a different local stoichiometry of the unit cells at the surface and interface. Complicating our understanding of the electronic properties of catalytically relevant complex oxide surfaces is the fact that at their surfaces and interfaces the broken translational symmetry fundamentally changes the properties 9, 10 . While this has been shown to produce remarkable physics at interfaces [11][12][13] , at surfaces of three-dimensional (3D) perovskites the results are qualitatively different: many fully oxygenated 3D perovskite surfaces and interfaces exhibit a so-cal...

show abstract

Thickness-dependent magnetotransport in ultrathin manganite films

Cited by 374 publications

References 11 publications

Colossal magnetocapacitance and scale-invariant dielectric response in phase-separated manganites

Colossal magnetocapacitance and scale-invariant dielectric response in phase-separated manganites

Impact of substrate on magnetic phase coexistence in bicritical Sm0.53Sr0.47MnO3 thin films

A persistent metal–insulator transition at the surface of an oxygen-deficient, epitaxial manganite film

Contact Info

Product

Resources

About