Anisotropic thermoelectric properties in layered cobaltite AxCoO2 (A=Sr and Ca) thin films

Kanno, Tsutomu; Yotsuhashi, Satoshi; Adachi, Hideaki
August 2004
Applied Physics Letters;8/2/2004, Vol. 85 Issue 5, p739
Academic Journal
We have fabricated epitaxial thin films of layered cobaltite AxCoO2 (A=Sr and Ca) on sapphire substrates by rf magnetron sputtering. The grown phase in the AxCoO2 films was found to be a monoclinic β-phase of primitive layered cobaltites and the epitaxial orientation of the film could be controlled by the surface plane of the substrates. The resistivity parallel to the CoO2 layers ρ∥ for the β-SrxCoO2 is as low as 2 mΩ cm at room temperature and shows metallic behavior. The ratio of perpendicular resistivity ρ⊥ to ρ∥ increases from 20 at room temperature to 90 at 3 K. More isotropic nature was observed in the Seebeck coefficient. Parallel Seebeck coefficients S∥ of AxCoO2 are approximately 60 μV/K at room temperature and the perpendicular S⊥ are about half of S∥.


Related Articles

  • Ferroelectric (Pb,La)(Zr,Ti)O3 epitaxial thin films on sapphire grown by rf-planar magnetron sputtering. Adachi, Hideaki; Mitsuyu, Tsuneo; Yamazaki, Osamu; Wasa, Kiyotaka // Journal of Applied Physics;7/15/1986, Vol. 60 Issue 2, p736 

    Deals with a study which described several approaches to the deposition of epitaxial transparent ferroelectric thin films on sapphire grown by radio frequency-planar magnetron sputtering. Discussion on thin films of ferroelectric materials; Methodology of the study; Results and discussion.

  • Direct formation of ordered CoPt and FePt compound thin films by sputtering. Visokay, M.R.; Sinclair, R. // Applied Physics Letters;3/27/1995, Vol. 66 Issue 13, p1692 

    Synthesizes the epitaxial c-axis oriented ordered CoPt and FePt alloy films by cosputtering. Direct production of equiatomic FePt and CoPt films by dc magnetron cosputtering from elemental sources; Differences in the rotation spectra; Determination of anisotropic values from peak-to-peak torque...

  • Epitaxial Y-Ba-Cu-O thin films prepared by rf-magnetron sputtering. Setsune, K.; Kamada, T.; Adachi, H.; Wasa, K. // Journal of Applied Physics;8/1/1988, Vol. 64 Issue 3, p1318 

    Presents a study which prepared epitaxial yttrium-barium-copper-oxygen thin films by radio frequency-magnetron sputtering. Experimental details; Results and discussion; Conclusion.

  • X-ray and Raman analyses of GaN produced by ultrahigh-rate magnetron sputter epitaxy. Park, Minseo; Maria, J.-P.; Cuomo, J. J.; Chang, Y. C.; Muth, J. F.; Kolbas, R. M.; Nemanich, R. J.; Carlson, E.; Bumgarner, J. // Applied Physics Letters;9/2/2002, Vol. 81 Issue 10, p1797 

    Thick films of GaN were studied by x-ray diffraction and Raman spectroscopy. The GaN thick films were deposited on (0001) sapphire using ultrahigh-rate magnetron sputter epitaxy with typical growth rates as high as 10-60 µm/min. The width of the x-ray rocking curve from the (0002) reflection...

  • Microwave intermodulation distortion of MgB[sub 2] thin films. Lamura, G.; Purnell, A. J.; Cohen, L. F.; Andreone, A.; Chiarella, F.; Gennaro, E. Di; Vaglio, R.; Hao, L.; Gallop, J. // Applied Physics Letters;6/23/2003, Vol. 82 Issue 25, p4525 

    The two-tone intermodulation arising in MgB[SUB2] thin films deposited in situ by planar magnetron sputtering on sapphire substrates is studied. Samples are characterized using an open-ended dielectric puck resonator operating at 8.8 GHz. The experimental results show that the third-order...

  • High resolution and analytical electron microscopy of ZnO layers doped with magnetic ions for spintronic applications. Abouzaid, M.; Ruterana, P.; Liu, C.; Morkoç, H. // Optica Applicata;2006, Vol. 36 Issue 2/3, p311 

    We have investigated the effect of temperature on the crystalline quality of (Zn, Mn)O thin films prepared by rf magnetron sputtering using c-plane sapphire substrates. The layers comprised an Mn doped part towards the surface on top of about a 150 nm pure ZnO layer. They exhibit a columnar...

  • YBa[sub 2]Cu[sub 3]O[sub 7] thin films grown on sapphire with epitaxial yttria-stabilized.... Chen, L.F.; Chen, P.F. // Applied Physics Letters;11/16/1992, Vol. 61 Issue 20, p2412 

    Examines the epitaxial growth of yttria-stabilized zirconia (YSZ) buffer layers on sapphire substrates using rf magnetron sputtering method. Use of standard four-probe method to measure the resistive transition curve of YSZ sapphire; Deposition of YBa[sub 2]Cu[sub 3]O[sub 7] thin films on YSZ...

  • Improved tunnel magnetoresistance characteristics of magnetic tunnel junctions with a Heusler alloy thin film of Co2MnGe and a MgO tunnel barrier. Hakamata, Shinya; Ishikawa, Takayuki; Marukame, Takao; Matsuda, Ken-ichi; Uemura, Tetsuya; Arita, Masashi; Yamamoto, Masafumi // Journal of Applied Physics;5/1/2007, Vol. 101 Issue 9, p09J513 

    We fabricated magnetic tunnel junctions (MTJs) with a Co-based full-Heusler alloy thin film of Co2MnGe (CMG) and a MgO tunnel barrier. The microfabricated MTJs with a Co-rich CMG film showed relatively high tunnel magnetoresistance ratios of 83% at room temperature and 185% at 4.2 K. These...

  • Growth of Ti3SiC2 thin films by elemental target magnetron sputtering. Emmerlich, Jens; Högberg, Hans; Sasvári, Szilvia; Persson, Per O. Å.; Hultman, Lars; Palmquist, Jens-Petter; Jansson, Ulf; Molina-Aldareguia, Jon M.; Czigány, Zsolt // Journal of Applied Physics;11/1/2004, Vol. 96 Issue 9, p4817 

    Epitaxial Ti3SiC2(0001) thin films have been deposited by dc magnetron sputtering from three elemental targets of Ti, C, and Si onto MgO(111) and Al2O3(0001) substrates at temperatures of 800-900 ° C. This process allows composition control to synthesize Mn+1 AXn (MAX) phases (M: early...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics