APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

28 Feb 2011

Volume 98, Issue 9, Articles (09xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 98, 093502 (2011); http://dx.doi.org/10.1063/1.3531756 (3 pages)

Marina S. Leite, Robyn L. Woo, William D. Hong, Daniel C. Law, and Harry A. Atwater
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Molecular beam epitaxial growth of BaTiO3 single crystal on Ge-on-Si(001) substrates

C. Merckling, G. Saint-Girons, C. Botella, G. Hollinger, M. Heyns, J. Dekoster, and M. Caymax

Appl. Phys. Lett. 98, 092901 (2011); http://dx.doi.org/10.1063/1.3558997 (3 pages) | Cited 3 times

Online Publication Date: 1 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thin films of perovskite type BaTiO3 (BTO) oxide have been grown epitaxially directly on Ge(001) surface at high temperature using molecular beam epitaxy. A stable (2×1) BaGex surface periodicity is the critical enabling template for subsequent BTO heteroepitaxy on Ge(001). Reflection high energy electron diffraction (RHEED) and transmission electron microscopy indicate that high quality heteroepitaxy on Ge-on-Si(001) take place with 〈100〉BTO(001)∥〈110〉Ge(001) confirming a 45° rotation epitaxial relationship. X-ray diffraction has been used to study the BTO lattice parameters and we evidenced that both tetragonal and cubic phases of BTO are present in the epilayer.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.aj Insulators
61.05.jh Low-energy electron diffraction (LEED) and reflection high-energy electron diffraction (RHEED)

Conductive atomic force microscopy studies on dielectric breakdown behavior of ultrathin Al2O3 films

K. Ganesan, S. Ilango, S. Mariyappan, M. Farrokh Baroughi, M. Kamruddin, and A. K. Tyagi

Appl. Phys. Lett. 98, 092902 (2011); http://dx.doi.org/10.1063/1.3560307 (3 pages) | Cited 1 time

Online Publication Date: 1 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ultrathin films of Al2O3 prepared by atomic layer deposition have been subjected to local electrical stress analysis using conducting atomic force microscopy. The loss of local dielectric integrity through current leakage in these extremely thin films is studied using scanning spreading resistance imaging. Our experimental results shows that repeated voltage stress progressively increases number of leakage spots. While the density of leakage spots increase with higher applied bias for thin oxide films, initial increase and reduction in leakage spots are observed for thick films.
Show PACS
77.22.Jp Dielectric breakdown and space-charge effects
77.22.Gm Dielectric loss and relaxation
68.55.-a Thin film structure and morphology
77.55.-g Dielectric thin films
68.37.Ps Atomic force microscopy (AFM)

Shape of ferroelectric domains in LiNbO3 and LiTaO3 from defect/domain-wall interactions

Donghwa Lee (이동화), Haixuan Xu (徐海譞), Volkmar Dierolf, Venkatraman Gopalan, and Simon R. Phillpot

Appl. Phys. Lett. 98, 092903 (2011); http://dx.doi.org/10.1063/1.3560343 (3 pages) | Cited 3 times

Online Publication Date: 1 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The observed orientations and shapes of ferroelectric domains in stoichiometric and congruent LiTaO3 and LiNbO3 are explained in terms of the differences in the energetics of domain walls, and the energetics of defect/domain-wall interactions. Density functional theory calculations show that the energy of a Y-wall, parallel to (11math0), is lower than that of the X-walls, parallel to (10math0), in both stoichiometric LiNbO3 and LiTaO3. As a result the domains are hexagonal and delineated by Y-walls. In congruent LiTaO3, the interaction of antisite defects with domains walls can reverse this order of stability, leading to triangular domains delineated by one type of X-wall. In congruent LiNbO3, the interactions of the antisite defects with the domain walls are too weak to reverse the order of stability of the domains walls; as a result the domains remain hexagonal.
Show PACS
77.80.Dj Domain structure; hysteresis
61.66.Bi Elemental solids
61.66.Dk Alloys
77.84.Ek Niobates and tantalates
61.72.J- Point defects and defect clusters

Low temperature processed bilayer dielectrics for low-voltage flexible saturated load inverters

Ye Zhou, V. A. L. Roy, Zong-Xiang Xu, H. Y. Kwong, Hai-Bo Wang, and C. S. Lee

Appl. Phys. Lett. 98, 092904 (2011); http://dx.doi.org/10.1063/1.3558913 (3 pages) | Cited 3 times

Online Publication Date: 1 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Saturated load inverters using low temperature processed bilayer n-octadecylphosphonic acid (ODPA)/Al2O3 dielectrics were fabricated on flexible polyethylene terephthalate substrates. The saturated load inverters, which enable simplified processing, could operate at supply voltage as low as –2 V and achieve a gain up to 23 at –5 V. The inverters on ODPA/Al2O3 exhibited better mechanical stability upon bending due to the existence of self-assembled monolayer ODPA, implying their potential application in low voltage inexpensive flexible electronics.
Show PACS
84.32.Tt Capacitors
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
84.30.Jc Power electronics; power supply circuits

Enhanced resonant magnetoelectric coupling in frequency-tunable composite multiferroic bimorph structures

P. Finkel, J. Bonini, E. Garrity, K. Bussman, J. Gao, J. F. Li, S. E. Lofland, and D. Viehland

Appl. Phys. Lett. 98, 092905 (2011); http://dx.doi.org/10.1063/1.3560055 (3 pages) | Cited 6 times

Online Publication Date: 3 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on a giant tunable enhanced resonant magnetoelectric (ME) coupling in multiferroic magnetostrictive/piezoelectric composite bimorph structures. The approach uses a magnetic/electric field assisted stress-reconfigurable resonance to produce frequency tuning of up to 100%. The studies were performed by laser Doppler spectroscopy. We also show that this principle of a continuously tuned resonance might be used to improve sensitivity for ME magnetic sensors.
Show PACS
77.55.Nv Multiferroic/magnetoelectric films
75.85.+t Magnetoelectric effects, multiferroics
75.80.+q Magnetomechanical effects, magnetostriction

SiO2/Si interfaces on high-index surfaces: Re-evaluation of trap densities and characterization of bonding structures

Shoichi Ogata, Shinya Ohno, Masatoshi Tanaka, Takahiro Mori, Tsuyoshi Horikawa, and Tetsuji Yasuda

Appl. Phys. Lett. 98, 092906 (2011); http://dx.doi.org/10.1063/1.3561741 (3 pages)

Online Publication Date: 4 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Interface trap densities, Dit, at the thermally oxidized Si surfaces were investigated for the (001), (111), (110), (120), (331), and (113) orientations. The oxides were formed by dry or wet oxidation in the temperature range of 700–950 °C. Dit took a maximum not only on the (111) surfaces but also on (110). Low Dit values were obtained on wet-oxidized high-index surfaces. Correlation between Dit and the interface anisotropy observed by reflectance difference spectroscopy suggests preferential oxidation of the Si atoms with the (111)-like bonding geometry on the (113) surfaces.
Show PACS
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
68.35.Ct Interface structure and roughness
81.65.Mq Oxidation
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Anomalous Curie temperature behavior of A-site Gd-doped BaTiO3 ceramics: The influence of strain

Liubin Ben and Derek C. Sinclair

Appl. Phys. Lett. 98, 092907 (2011); http://dx.doi.org/10.1063/1.3563710 (3 pages) | Cited 3 times

Online Publication Date: 4 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The influence of A-site Gd3+ doping on the c/a ratio, cell volume and Curie temperature (Tc) of ferroelectric BaTiO3 according to the titanium vacancy mechanism, viz., Ba1−xGdxTi1−x/4O3 has been investigated and compared to that of La3+-doping. The c/a ratio and cell volume of Gd-doped samples are larger than the equivalent La-doped samples and Tc decreases at a rate of only ∼ 8 °C/at. % for Gd3+ substitution compared to ∼ 24 °C/at. % for La3+ substitution. These trends are opposite to that expected based on ionic-radii and tolerance factor arguments. This anomalous behavior is attributed to an ion-size mismatch (cation variance) effect on the A-site between the Ba2+ and Gd3+ ions that induces local strain in the lattice that suppresses the reduction in the c/a ratio and cell volume, and as a consequence in the rate of decrease in Tc.
Show PACS
77.80.bn Strain and interface effects
61.72.up Other materials
61.72.jd Vacancies

Fully-inverted piezoresponse hysteresis loops mediated by charge injection in 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3 single crystals

Qian Li, Yun Liu, Jason Schiemer, Paul Smith, Zhenrong Li, Ray L. Withers, and Zhuo Xu

Appl. Phys. Lett. 98, 092908 (2011); http://dx.doi.org/10.1063/1.3562034 (3 pages) | Cited 8 times

Online Publication Date: 4 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The domain structure and local switching behavior of ternary relaxor (001) 0.29Pb(In1/2Nb1/2)O3–0.44Pb(Mg1/3Nb2/3)O3–0.27PbTiO3 single crystals are studied using piezoresponse force microscopy. The as-grown crystals exhibit a labyrinthine domain pattern similar to other relaxor-based ferroelectrics. Abnormally switched domains are observed for both positive and negative tip-voltages, with sign-dependent thresholds and growth rates on the poled crystals. Further piezoresponse hysteresis loop measurements show that fully inverted loops can be observed under high switching voltages, mediated by injected charge fields. The dynamic behavior of the observed abnormal switching is qualitatively analyzed and the underlying mechanisms discussed.
Show PACS
77.80.Dj Domain structure; hysteresis
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
77.80.Fm Switching phenomena

Order–disorder behavior of ferroelectric phase transition of KTa1−xNbxO3 probed by Brillouin scattering

Ryu Ohta, Junta Zushi, Takuma Ariizumi, and Seiji Kojima

Appl. Phys. Lett. 98, 092909 (2011); http://dx.doi.org/10.1063/1.3560345 (3 pages) | Cited 4 times

Online Publication Date: 4 March 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The precursor dynamics of a cubic–tetragonal ferroelectric phase transition of potassium tantalate niobate (KTa1−xNbxO3 with x = 0.32) crystals is studied by Brillouin scattering. The appearance of the central peak (CP) and marked softening of the elastic constant c11 are clearly observed above the Curie temperature, TC–T, owing to the interaction between the LA mode and local polarization fluctuations of polar nanoregions (PNRs). The relaxation time determined by the CP width clearly shows a critical slowing down above TC–T, indicating an order–disorder feature of the ferroelectric phase transition. The size of a dynamic PNR is evaluated, and it increases toward TC–T.
Show PACS
77.80.B- Phase transitions and Curie point
78.35.+c Brillouin and Rayleigh scattering; other light scattering
81.30.Hd Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder
64.60.Cn Order-disorder transformations
77.22.Ej Polarization and depolarization
77.22.Gm Dielectric loss and relaxation
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close