Onset of metallic behavior in strained<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mtext>LaNiO</mml:mtext></mml:mrow><mml:mn>3</mml:mn></mml:msub></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow><mml:mi>n</mml:mi></mml:msub><mml:mo>/</mml:mo><mml:msub><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mtext>SrMnO</mml:mtext></mml:mrow><mml:mn>3</mml:mn></mml:msub

May, Steven J.; Santos, Tiffany S.; Bhattacharya, Anand

doi:10.1103/physrevb.79.115127

Phys. Rev. B

2009

DOI: 10.1103/physrevb.79.115127

|View full text |Cite

Onset of metallic behavior in strained(LaNiO3)n/(SrMnO3

Steven J. May

Tiffany S. Santos

Anand Bhattacharya

Abstract: ͑LaNiO 3 ͒ n / ͑SrMnO 3 ͒ 2 superlattices were grown using ozone-assisted molecular beam epitaxy. In situ reflection high-energy electron diffraction and x-ray scattering has been used to characterize the structural properties of the superlattices, which are strained to the SrTiO 3 substrates. The superlattices exhibit excellent crystallinity and interfacial roughness of less than 1 unit cell. A metal-insulator transition is observed as n is decreased from 4 to 1. Analysis of the transport data suggests an evo… Show more

Help me understand this report

View preprint versions

Search citation statements

Order By: Relevance

Paper Sections

Select...

Citation Types

Supporting

Mentioning

Contrasting

Year Published

2011

2022

Publication Types

Select...

Article9

Relationship

Self Cite1

Independent8

Authors

Journals

Cited by 59 publications

(58 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…LNO based heterostructures have been grown and transport measurements have revealed a MI transition as the LNO thickness is reduced to only a few unit cells (u.c.) [9,10]. This behaviour is in agreement with the MI transition observed in single ultrathin LNO films [11].…”

supporting

confidence: 78%

Metal-Insulator Transition in UltrathinLaNiO3Films

et al. 2011

View full text Add to dashboard Cite

Transport in ultrathin films of LaNiO3 evolves from a metallic to a strongly localized character as the film's thickness is reduced and the sheet resistance reaches a value close to h/e 2 , the quantum of resistance in two dimensions. In the intermediate regime, quantum corrections to the Drude lowtemperature conductivity are observed; they are accurately described by weak localization theory. Remarkably, the negative magnetoresistance in this regime is isotropic, which points to magnetic scattering associated with the proximity of the system to either a spin glass state or the charge ordered antiferromagnetic state observed in other rare earth nickelates.Complex oxides are exciting materials in which the interplay between charge, spin, orbital and lattice degrees of freedom leads to a wealth of novel and exotic phenomena. Among these materials, LaNiO 3 (LNO), a metal and paramagnet lacking any ordering phenomena in bulk [1][2][3], has recently become the subject of intense research. This was mainly triggered by theoretical work [4] which suggested the possibility of orbital ordering and high-T c superconductivity in superlattices where very thin LNO layers are separated by insulating layers, confining the conduction to two dimensions (2D). These predictions have yet to be confirmed experimentally. LNO bulk and thin films have been extensively studied in the past, showing a large effective mass and enhanced Pauli paramagnetism, which has been attributed to strong correlations [1,2,5]. This material has also been reported to be sensitive to the degree of disorder. For instance, increasing the amount of oxygen vacancies can lead to weak localization and metal-insulator (MI) transitions, as well as antiferromagnetic ordering and spin glass behaviour [6][7][8]. LNO based heterostructures have been grown and transport measurements have revealed a MI transition as the LNO thickness is reduced to only a few unit cells (u.c.) [9,10]. This behaviour is in agreement with the MI transition observed in single ultrathin LNO films [11]. Understanding the nature of transport for this compound in the ultrathin limit appears essential for future investigation of LNO-based heterostructures and serves as the motivation for this work. Upon reduction of the LNO thickness, transport evolves from a metallic to a strongly localized behavior as the room temperature sheet resistance approaches h/e 2 ∼ 25 kΩ, the quantum of resistance in 2D. We find a transition region between the metallic and the strongly localized states where the films show an upturn in the resistivity at low temperatures which can be explained by the theory of weak localization. Surprisingly, the magnetoresistance (MR) is found to be isotropic in this regime. We attribute this to the presence of magnetic scattering and discuss its possible origins. Films were grown on (001) SrTiO 3 substrates by off-axis rf magnetron sputtering, leading to fully strained epi-

show abstract

supporting

confidence: 78%

Metal-Insulator Transition in UltrathinLaNiO3Films

et al. 2011

View full text Add to dashboard Cite

show abstract

“…studies revealed the composition of the superlattices, average c-axis parameters, and confirmed that they exhibit minimal interfacial mixing and are highly crystalline. 17 Synchrotron diffraction measured along the (00L), shown in Fig. 1(a (1 1 3) peaks confirm the epitaxial layers are coherently strained.…”

mentioning

confidence: 99%

“…17 The sample thicknesses are between 200 and 215Å. Previous structural (00L) in three samples exhibiting distinct satellite peaks due to the coherent superlattice structure (a).…”

mentioning

confidence: 99%

Control of octahedral rotations in (LaNiO3)n/(SrMnO

May

Smith²,

Kim³

et al. 2011

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

Oxygen octahedral rotations have been measured in short-period (LaNiO3)n/(SrMnO3)m superlattices using synchrotron diffraction. The in-plane and out-of-plane bond angles and lengths are found to systematically vary with superlattice composition. Rotations are suppressed in structures with m > n, producing a nearly cubic form of LaNiO3. Large rotations are present in structures with m < n, leading to reduced bond angles in SrMnO3. The metal-oxygen-metal bond lengths decrease as rotations are reduced, in contrast to behavior previously observed in strained, single layer films. This result demonstrates that superlattice structures can be used to stabilize non-equilibrium octahedral behavior in a manner distinct from epitaxial strain, providing a novel means to engineer the electronic and ferroic properties of oxide heterostructures.The ABO 3 perovskite oxides exhibit an array of physical properties making them attractive for applications in electronics and energy conversion. 1-3 Recent work has demonstrated that the functionality of these materials can be further expanded through the formation of superlattices, which can exhibit enhanced properties compared to bulk compounds. While the majority of work in this field has focused on the electronic and ferroic properties of oxide superlattices, 4-9 the impact of heterointerfaces on the local atomic structure has received less attention. 10-13 Of particular importance are the rotations and distortions of the BO 6 octahedra, which determine the B-O-B bond angles (θ) and B-O bond lengths (d). As both θ and d couple to the electronic bandwidth, a quantitative understanding of how octahedral rotations are modified in short-period superlattices is necessary in order to control novel electronic phenomena in oxide heterostructures.Motivated by the question of what octahedral behavior is stabilized at the interface between two structurally dissimilar perovskites, we have investigated the bond angles in a systematic series of (LaNiO 3 ) n /(SrMnO 3 ) 2 superlattices. In bulk, LaNiO 3 (LNO) exhibits robust octahedral rotations leading to θ = 165.2 • along all < 001 > directions, 14 with an a − a − a − rotation pattern. 15 In contrast, bulk SrMnO 3 (SMO) is a cubic perovskite (a 0 a 0 a 0 ) lacking octahedral rotations (θ = 180 • ). 16 Due to the short-period of the superlattices investigated and the geometric constraint requiring that the BO 6 octahedra maintain corner connectivity, the octahedral rotations remain coherent throughout the superlattices. We demonstrate that the in-plane and out-of-plane bond angles and lengths can be tuned by altering the superlattice composition [n/(n+m)], allowing for the stabilization of octahedral behavior that differs substantially from that found in bulk compounds.The (LNO) n /(SMO) m superlattices, herein referred to as LnSm, were deposited on SrTiO 3 substrates by ozoneassisted molecular beam epitaxy. 17 The sample thicknesses are between 200 and 215Å. Previous structural (00L) in three samples exhibiting distinct satellite peaks due to t...

show abstract

“…'s) [18][19][20]. Several explanations have been proposed in the literature, including Anderson localization, which occurs when the resistance exceeds a critical value (Mott minimum conductivity) below a certain thickness [19,21], and quantum confinement [22,23].…”

mentioning

confidence: 99%

Structural origins of the properties of rare earth nickelate superlattices

et al. 2013

View full text Add to dashboard Cite

NiO 6 octahedral tilts in the LaNiO 3 /SrTiO 3 superlattices are quantified using position averaged convergent beam electron diffraction in scanning transmission electron microscopy. It is shown that maintaining oxygen octahedra connectivity across the interface controls the octahedral tilts in the LaNiO 3 layers, their lattice parameters and their transport properties.Unlike films and layers that are connected on one side to the substrate, subsequent LaNiO 3 layers in the superlattice exhibit a relaxation of octahedral tilts towards bulk values. This relaxation is facilitated by correlated tilts in SrTiO 3 layers and is correlated with the conductivity enhancement of the LaNiO 3 layers in the superlattices relative to individual films.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Onset of metallic behavior in strained(LaNiO3)n/(SrMnO3

Cited by 59 publications

References 34 publications

Metal-Insulator Transition in UltrathinLaNiO3Films

Metal-Insulator Transition in UltrathinLaNiO3Films

Control of octahedral rotations in (LaNiO3)n/(SrMnO

Structural origins of the properties of rare earth nickelate superlattices

Contact Info

Product

Resources

About