Published May 4, 2015 | Version v1
Journal article Metadata-only

Direct correlation and strong reduction of native point defects and microwave dielectric loss in air-annealed (Ba,Sr)TiO3

Creators

  • 1. Department of Electrical and Computer Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)
  • 2. Naval Research Laboratory, Washington, DC 20375 (United States)
  • 3. Department of Physics and Center for Materials Research, The Ohio State University, Columbus, Ohio 43210 (United States)

Description

We report on the native defect and microwave properties of 1 μm thick Ba0.50Sr0.50TiO3 (BST) films grown on MgO (100) substrates by molecular beam epitaxy (MBE). Depth-resolved cathodoluminescence spectroscopy (DRCLS) showed high densities of native point defects in as-deposited BST films, causing strong subgap emission between 2.0 eV and 3.0 eV due to mixed cation VC and oxygen Vo vacancies. Post growth air anneals reduce these defects with 2.2, 2.65, and 3.0 eV VO and 2.4 eV VC intensities decreasing with increasing anneal temperature and by nearly two orders of magnitude after 950 °C annealing. These low-defect annealed BST films exhibited high quality microwave properties, including room temperature interdigitated capacitor tunability of 13% under an electric bias of 40 V and tan δ of 0.002 at 10 GHz and 40 V bias. The results provide a feasible route to grow high quality BST films by MBE through post-air annealing guided by DRCLS

Additional details

Identifiers

DOI
10.1063/1.4919891;

Publishing Information

Journal Title
Applied Physics Letters
Journal Volume
106
Journal Issue
18
Journal Page Range
p. 182903-182903.5
ISSN
0003-6951
CODEN
APPLAB

INIS

Country of Publication
United States
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
46104707
Subject category
S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;
Descriptors DEI
ANNEALING; BARIUM COMPOUNDS; CATHODOLUMINESCENCE; CATIONS; CORRELATIONS; DIELECTRIC MATERIALS; EMISSION SPECTROSCOPY; FILMS; GHZ RANGE; MAGNESIUM OXIDES; MICROWAVE RADIATION; MOLECULAR BEAM EPITAXY; STRONTIUM TITANATES; SUBSTRATES; VACANCIES
Descriptors DEC
ALKALINE EARTH METAL COMPOUNDS; CHALCOGENIDES; CHARGED PARTICLES; CRYSTAL DEFECTS; CRYSTAL GROWTH METHODS; CRYSTAL STRUCTURE; ELECTROMAGNETIC RADIATION; EMISSION; EPITAXY; FREQUENCY RANGE; HEAT TREATMENTS; IONS; LUMINESCENCE; MAGNESIUM COMPOUNDS; MATERIALS; OXIDES; OXYGEN COMPOUNDS; PHOTON EMISSION; POINT DEFECTS; RADIATIONS; SPECTROSCOPY; STRONTIUM COMPOUNDS; TITANATES; TITANIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS

Optional Information

Notes
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