XClose

Condensed Matter & Materials Physics

Home
Menu

Research

fig_13_AdvMat_CrSTO_1
Ultralow contact resistance at an epitaxial metal/oxide heterojunction through interstitial site doping Heteroepitaxial growth of Cr metal on Nb-doped SrTiO3(001) is accompanied by Cr diffusion to interstitial sites within the first few atomic planes, an anchoring of the Cr film to the substrate, charge transfer from Cr to Ti, and metallization of the near-surface region, The contact resistance of the resulting interface is exceedingly low. More...

fig_13_AFM_LCO_defects_2
The impacts of cation stoichiometry and substrate surface quality on nucleation, structure, defect formation, and intermixing in complex oxide heteroepitaxy - LaCrO3 on SrTiO3(001). Our ability to design and fabricate electronic devices using complex oxides is critically dependent on our ability to controllably synthesize these materials in thin-film form. Here we investigate thin films of LaCrO3 on SrTiO3(001) and find that this material can accommodate La-to-Cr ratios which differ from unity by as much as ~15% in the Cr rich direction without extensive loss of structural quality. More...

fig_13_PRL_LCO_absorption_2
Multiband optical absorption controlled by lattice strain in thin-film LaCrO3. Complex oxide heterostructures may exhibit properties not observed in the bulk phases of the individual constituents. Accordingly, it is of interest to engineer structures with novel optical properties by combining materials with specific electronic structure features. However, it is essential to first understand the detailed nature of the optical absorption bands and effect of strain on these individual complex oxides. More...

fig_13_JPCL_SiO2_BTO
Neutral and charged oxygen vacancies induce two-dimensional electron gas near SiO2/BaTiO3 interfaces. Nanoparticles of BaTiO3 coated with silica have the dielectric constant over 105. We explore the role of defects at the a-SiO2/BaTiO3 (001) interface and demonstrate that the bonding between silica and BaTiO3 leads to the formation of a polar region that traps neutral oxygen vacancies. In turn, these vacancies give rise to the quasi-two-dimensional electron gas. More...

fig_12_PRL_Ovac_axial
Defect-mediated lattice relaxation and domain stability in ferroelectric oxides. Oxygen vacancies transform between their metastable equatorial and stable axial configurations via diffusion or rotation of the polar axis near the vacancy. This mechanism, predicted to dominate in materials with slow oxygen vacancy diffusion and low formation energy of 90° domain walls, can stimulate the formation of domains with their polar axes pinned by the vacancies. More...

fig_12_LNMO_SEM
High-performance LiNi0.5Mn1.5O4 spinel controlled by Mn3+concentration and site disorder. The electrochemical properties displayed by LiNi0.5Mn1.5O4 spinel, one of the most promising cathode materials for Li-ion batteries, are intrinsically related to the Ni-Mn site disorder and the amount of residual Mn3+ ions, which can be tuned through post-synthesis annealing and element substitution. More...

fig_12_Si_Nitro
Selective response of mesoporous silicon to adsorbants with nitro groups. Mesoporous silicon shows molecule-specific response when exposed to vapours of explosive (TNT and RDX) and non-explosive (NT) materials: the molecules adsorb and decompose at the Si surface, thus, changing the electronic properties of the near-surface region. This observation provides a pathway for the development of inexpensive and selective sensor of explosives. More...

fig_11_C12A7_4e
Spectroscopic characterization of a multiband complex oxide: Insulating and conducting cement 12CaO · 7Al2O3. Detailed spectroscopic analysis of the electronic structure of a complex nanoporous oxide in its insulating ([Ca24Al28O64]4+ · 2O2-) and metallic ([Ca24Al28O64]4+ · 4e-) forms. More...

fig_11_PNNL-micrograph
Band alignment, built-in potential and the absence of conductivity at the LaCrO3/SrTiO3(001) heterojunction. In order to advance microelectronic technologies, scientists and engineers are on the lookout for new semiconductor materials that can be used to control the flow of electrons in nanoscale devices. One of the promising directions is to exploit interfaces of so-called non-polar and polar oxides. The former are composed of neutral atomic planes, while in the latter the atomic planes have alternating charge. More...

fig_11_JPCC_CaO_cover
Exciton-driven highly hyperthermal O-atom desorption from nanostructured CaO. We report qualitatively new highly hyperthermal oxygen atom emission from nanostructured CaO excited by 6.4 eV nanosecond laser pulses. The kinetic energy distribution of emitted O-atoms peaks at 0.7 eV, which is over 4 times greater than previously observed for hyperthermal oxygen atom emission and approximately 20 times greater than the peak of the thermal kinetic energy distribution. More...

fig_10_LAOSTO_mixed
Instability, intermixing and electronic structure at the epitaxial LaAlO3/SrTiO3(001) heterojunction. We investigate the sructure of epitaxial LAO / STO interface using several independent analytical methods and ab initio simulations. Contrary to the widely accepted view, we show that interfacial intermixing is energetically preferable to abruptness, and that forming an intermixed interface represents a thermodynamically favorable process. More...