Properties of the magnetoresistive La 0.8 Sr 0.2 MnO 3 film and integration with PbZr 0.52 Ti 0.48 O 3 ferroelectrics
- PDF / 752,877 Bytes
- 6 Pages / 412.92 x 637.2 pts Page_size
- 48 Downloads / 197 Views
Properties of the magnetoresistive La0*.Sro0 2MnO 3 film and integration with PbZr0 .5 2Ti0 .48 0 3 ferroelectrics Fumiaki Mitsugi , Tomoaki Ikegamil, Kenji Ebiharal, J. Narayan2 and A. M. Grishin 'Department of the Electrical and Computer Engineering, Kumamoto University, Kurokami, 2Kumamoto 860-8555, Japan Department of the Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7916, USA 3Department of Condensed Matter Physics, Royal Institute of Technology, S- 10044 Stockholm, Sweden
ABSTRACT The colossal magnetoresistive La 0.8Sr 0.2MnO 3 (LSMO) thin film was prepared on the MgO (100) single crystal substrate using KrF excimer pulsed laser deposition technique. The LSMO film deposited at the substrate temperature of 850 'C, oxygen pressure of 500 mTorr and laser energy density of 2 J/cm 2 (5 Hz) showed the resistivity peak temperature (Tp) of 330 K and the magnetoresi stance change of 15 % (H=0.7 T) at the room temperature. The large lattice mismatch with the substrate increased Tp and decreased the resistivity of the LSMO film. The X-ray diffraction measurement for the PbZr0 .52Ti0 .480 3 (PZT) / LSMO heterostructures indicated both c-axis and in- plane orientation, with the good PZT surface morphology.
INTRODUCTION Perovskite manganites of the Re, -AeMnO3 (Re : rare earth elements, Ae : alkaline earth elements) have potential for various device applications such as magnetic field sensor, hard disk read head and infrared bolometer due to the negative colossal magnetoresistance (CMR) effect. The basic manganite of ReMnO 3 is an anti ferromagnetic insulator. A substitution of the divalent Ae 2' for the trivalent Re 3' makes Mn 33(tS2g eg') / Mn4'(t 32geg0) mixed valence state. The electron hopping from Mn 3- to Mn4- by a Mn-O-Mn path results in ferromagnetic ordering and metallic conductivity. The electron (hole) transfer between the neighboring sites can be expressed as t11 t0 cos (Oj / 2) [1]. In this equation, 0,, is the relative angle between the neighboring spins. The Mn3 1/ Mn4 ratio, Mn-O-Mn bond length and bond angle have an effect on the transfer property. The sizes of the Re3- ion and Ae 2 ion change the Mn-O-Mn bond length and the many materials such as Lal-,CaMnO 3, Laj_,BaMnO 3, La,._SrMnO 3, Ndl-,SrMnO 3 have been researched. We have studied La1_,SrMnO3 system. The large radii of La 3- ion (L.15A) and Sr>+(1.13A) ion shorten the Mn-O-Mn bond length, which results in high resistivity peak temperature (Tp) [2]. The bulk La1-,SrMnO 3 has ferromagnetic insulator - ferromagnetic metal transition at x=0. 17 [3]. We report the properties of x=0.20 Lal-xSrxMnO 3 thin film. We have also tried to integrate the CMR film with ferroelectric film. The ferroelectrics / CMR heterostructures have a potential for not only ferroelectric field effect transistor, but also new device which works under both electric and magnetic field.
J3.23.1
In this paper, we investigated the structural and electrical properties of the Lao.8Sro. 2 MnO 3 (LSMO) film deposited on MgO (100) s
Data Loading...
