Lead palladium zirconate titanate: A room temperature nanoscale multiferroic thin film

Abstract

The discovery of single-phase multiferroic materials and the understanding of intriguing physics of the coupling mechanisms between their spin and polarization is important for the next generation of multifunctional devices. In this work, we report dielectric, ferroelectric, and magnetization results of Pdsubstituted room-temperature magnetoelectric multiferroic Pb(Zr 0.20 Ti 0.80) 0.7 Pd 0.3 O 3 (PZTPd) thin films. Highly c-axis oriented PZTPd thin films were grown on {(LaAlO 3) 0.3 (Sr 2 AlTaO 6) 0.7 } (LSAT) substrates using pulsed laser deposition technique. These films were phase pure and stabilized in tetragonal phase. Atomic force microscopic studies indicated a homogeneous distribution of grains on the films' surface with a surface roughness (R Q) of ~5.4 nm. A large dielectric constant of ~1780 and a low loss tangent value of ~0.52 were observed at 1 kHz measured at room temperature. Temperature dependent dielectric studies on Pt/PZTPd/La 0.7 Sr 0.3 MnO 3 (LSMO) metal-insulator-metal heterostructure capacitors between 80-660 K indicated a diffused ferroelectric to paraelectric phase transition around 515 K. The polarization hysteresis loops observed at room temperature were attributed to its ferroelectric behavior. Saturated magnetization hysteresis loop with remanent magnetization of 1.54 emu/cm 3 was obtained at room temperature. Ferromagnetic ordering in thin films was found to sustain in the entire temperature range from 5-395 K, as revealed from the constant behavior of dM/dT curve with temperature. The mixed oxidation states of palladium (Pd 2+ /Pd 4+) dispersed in the polar Pb(Zr0.20Ti0.80)O 3 matrix were revealed from our high resolution x-rays photoelectron spectroscopic studies, and is ascribed to the origin of ferromagnetic ordering in the film. These findings suggest that PZTPd thin films are multiferroic (ferroelectricferromagnetic) at room temperature.

Characterization of V2O3 Nanoscale Thin Films Prepared by DC Magnetron Sputtering Technique

“…Figure 5 shows the ZFC and FC magnetization curves measured from the thin films at 100-1000 Oe. The ZFC and FC magnetization curves followed different paths up to applied field of 1000 Oe, that suggests that magnetization is related to the sample cooling history, which is typically observed in other magnetic systems [27,28]. These magnetization curves showed a small kink around 55 K at 100 Oe (Figure 5a) and that shifted to lower temperature at higher applied fields.…”

Room-Temperature, Nanoscale Multiferroic Pb(Fe0.5Ta0.5)1−x(Zr0.53Ti0.47)xO3 (x = 0.2, 0.3) Thin Films Grown via the Pulsed Laser Deposition Technique

“…[8] and Pd-doped Pb(Zr 0.20 Ti 0.80 ) 0.7 , refs. [9,10], among which the most well-studied material is BiFeO 3 [7]. This material, however, possesses weak magnetoelectric (ME) coupling and a large leakage current which prevents the integration of the material in practical device applications.…”

“…Room-temperature multiferroics in thin films are the clear choice for next-generation nanoelectronics, magnetic devices, spintronics, and memory device applications [7,21,22]. With the advancement of thin-film growth technology, high-purity, nanoscale epitaxial/polycrystalline multiferroic thin films can be fabricated on different substrates via several physical vapor deposition techniques, including the pulsed laser deposition (PLD) method [9], facilitating a platform for for researchers to discover and analyze magnetoelectric coupling in nanostructured thin films. Interestingly, Sr(Ti 0.65 Fe 0.35 )O 3-δ /SrTiO 3 thin films containing different oxygen defect concentrations were grown by the varying base pressure via the pulsed laser deposition method to study the role of the oxygen content in the magnetic behavior [23].…”