Epitaxial ferroelectric/giant magnetoresistive heterostructures for magnetosensitive memory cell

Abstract

Epitaxial ferroelectric/giant magnetoresistive Pb(Zr0.52Ti0.48)O3/La0.67Ca0.33MnO3 (PZT/LCMO) heterostructures have been grown onto LaAlO3 (001) single crystal by KrF pulsed laser deposition. Main processing parameters have been optimized to preserve giant magnetoresitivity in the LCMO film after deposition of the top ferroelectric layer. High degree of c-axis orientation and strong in-plane texture, coherent with the substrate, both in template LCMO and PZT layers, high dielectric permittivity of 720, remnant polarization of 17 μC/cm2 of PZT, and magnetoresistivity in LCMO of 28% at H=0.5 T indicate excellent characteristics of coexisting magnetoresistive and ferroelectric properties. We compare the performance of magnetosensitive memory cells with La0.67Ca0.33MnO3 and La0.75Sr0.25MnO3 giant magnetoresistive electrodes.

The size effect on transport properties of colossal magnetoresistance materials La0.67Ca0.33MnO3

“…Many new phenomena are anticipated to exhibit for further understanding of the underlying mechanism of the materials. Many multi-component oxides having interesting properties, such as superconductivity [1,2] , colossal magnetoresistivity (CMR) [3,4] and ferroelectricity, will play important roles in potential device applications of electronic devices, such as the high sensitive sensors [5] , field-effect transistors [6] and magnetosensitivie memories [7] . However, the fabrication and measurement of the multi-component oxides in such a small size are of great difficulties, and concerning superconductivity and colossal magnetoresistivity, only very few work has been reported recently.…”

Selective epitaxial growth of submicron complex oxide structures by amorphous SrTiO3

“…Many complex oxides exhibit interesting electrical behavior including high-T c superconductivity, colossal magnetoresistance (CMR) and ferroelectricity. Potential device applications including high sensitivity sensors, [1] flux flow transistors, [2] ferroelectric field effect transistors [3] and magnetic memory [4] require suitable microfabrication techniques. However, due to inherent stoichiometric and structural complexities associated with complex oxides, producing high quality sub-micron structures has proven difficult because conventional methods tend to require etching of the complex oxide.…”

Microstructure dependence of the electrical properties of (Ba,Sr)TiO3 thin film deposited on (La,Sr)MnO3 conductive layer

“…where the crystallographic planes and directions of LSMO and LAO are presented in the pseudocubic structure, and BST in the tetragonal structure [10]. Fig.…”

“…Meanwhile, some studies have been done on the colossal magnetoresistance material (La 1Àx Sr x ) MnO 3 as a candidate material for the bottom electrode layer [8][9][10][11]. This may be due to the following reasons.…”