Observation of depolarized ZnO(0001) monolayers: formation of unreconstructed planar sheets.

نویسندگان

  • C Tusche
  • H L Meyerheim
  • J Kirschner
چکیده

A novel nonpolar structure of 2 monolayer (ML) thick ZnO(0001) films grown on Ag(111) has been revealed, using surface x-ray diffraction and scanning tunneling microscopy. Zn and O atoms are arranged in planar sheets like in the hexagonal boron-nitride prototype structure. The observed depolarization is accompanied by a significant lateral 1.6% expansion of the lattice parameter and a 3% reduced Zn-O bond length within the sheets. The nonpolar structure stabilizes an atomically flat surface morphology unseen for ZnO surfaces thus far. The transition to the bulk wurtzite structure occurs in the 3-4 ML coverage range, connected to considerable roughening.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

CO oxidation over ZnO films on Pt(111) at near-atmospheric pressures

Well-ordered ultrathin ZnO(0001) films were grown on Pt(111) in a layer-by-layer mode. The reactivity of the films as a function of the film thickness and coverage was examined by the CO oxidation reaction at near-atmospheric pressures. At low temperatures ( 450 K), CO2 production is found to be much higher on the films of partial coverage than on dense ZnO(0001) films and bare Pt(111). Under r...

متن کامل

Photocatalytic Reduction of CO2 by ZnO Micro/nanomaterials with Different Morphologies and Ratios of {0001} Facets

ZnO microspheres, ZnO microflowers and ZnO nanorods are successfully synthesized via a convenient solvothermal method in distilled water-ethanol mixed medium. The as-prepared ZnO micro/nanomaterials are characterized by XRD, SEM, TEM, HRTEM, XPS, BET, and UV-Vis. The morphologies and exposed facets of the ZnO micro/nanomaterials can be controlled by simply changing the volume ratio of distilled...

متن کامل

Synthesize and Optical properties of ZnO: Eu Microspheres Based Nano-sheets at Direct and Indirect Excitation

Europium (Eu) doped ZnO microsphere based nano-sheets were synthesized through hydrothermal method. Effects of different concentrations of Europium on structural and optical properties of ZnO nano-sheets were investigated in detail. Prepared un-doped and Eu-doped ZnO samples were characterized using X-Ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron micro...

متن کامل

EFFECT OF FINISH ROLLING TEMPERATURE ON MICROSTRUCTURE,TEXTURE AND PLANAR ANISOTROPY IN ALUMINUM ALLOY AA3004 SHEETS

AA3004 alloy is widely used in can making. The major concern in the production of canbodies is earing, which develop by high planar anisotropy of rolled sheet. Balance ofrecrystallisation and rolling textures together with a uniform and fine grain microstructure canminimize the earing. The effects of finish rolling temperature (FRT) on planar anisotropy,microstructure, texture development and m...

متن کامل

Stabilization mechanism for the polar ZnO(0001̄)-O surface

When wurtzite ZnO is sliced perpendicular to the (0001) axis, two different polar surfaces, the (0001)-Zn and (0001̄)-O terminated surfaces, are formed. In a simple ionic picture, both surfaces are electrostatically unstable due to a diverging electrostatic energy. Although the ionic picture is an oversimplification, the surfaces adopt a modified surface structure to compensate for the polarity....

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Physical review letters

دوره 99 2  شماره 

صفحات  -

تاریخ انتشار 2007