Danyang Wang

Large recoverable energy density with excellent thermal stability in Mn‐modified NaNbO₃‐CaZrO₃ lead‐free thin films

Publisher: Wiley

Date: 13-03-2018

DOI: 10.1111/JACE.15528

Interface-Driven Multiferroicity in Cubic BaTiO3-SrTiO3 Nanocomposites

Publisher: American Chemical Society (ACS)

Date: 07-09-2022

DOI: 10.1021/ACSNANO.2C07215

Abstract: Perovskite multiferroics have drawn significant attention in the development of next-generation multifunctional electronic devices. However, the majority of existing multiferroics exhibit ferroelectric and ferromagnetic orderings only at low temperatures. Although interface engineering in complex oxide thin films has triggered many exotic room-temperature functionalities, the desired coupling of charge, spin, orbital and lattice degrees of freedom often imposes stringent requirements on deposition conditions, layer thickness and crystal orientation, greatly hindering their cost-effective large-scale applications. Herein, we report an interface-driven multiferroicity in low-cost and environmentally friendly bulk polycrystalline material, namely cubic BaTiO

Efficient and stable piezo-photocatalytic splitting of water and seawater by interfacial engineering of Na0.5Bi0.5TiO3/Na0.5Bi4.5Ti4O15 self-generated heterojunctions

Publisher: Elsevier BV

Date: 11-2023

DOI: 10.1016/J.NANOEN.2023.108830

Improved thermal stability of the piezoelectric properties of (Li, Ag)‐co‐modified (K, Na) NbO3‐based ceramics prepared by spark plasma sintering

Publisher: Wiley

Date: 03-04-2017

DOI: 10.1111/JACE.14838

Enhancing the triboelectricity of stretchable electrospun piezoelectric polyvinylidene fluoride/boron nitride nanosheets composite nanofibers

Publisher: Elsevier BV

Date: 12-2020

DOI: 10.1016/J.COCO.2020.100535

Anemia and Contributing Factors in Severely Malnourished Infants and Children Aged between 0 and 59 Months Admitted to the Treatment Centers of the Amhara Region, Ethiopia: A Multicenter Chart Review

Publisher: Hindawi Limited

Date: 27-03-2021

DOI: 10.1155/2021/6636043

Abstract: Background. Anemia among severely malnourished children is a double burden that could make the treatment outcome of severe acute malnutrition (SAM) more unfavorable. The burden and the factors are, however, uncovered among children in the Amhara region. Therefore, the study was aimed at determining the prevalence of anemia and identifying contributing factors in severely malnourished children aged between 0 and 59 months admitted to the treatment centers of the Amhara region referral hospitals. Methods. A facility-based cross-sectional study was conducted that included 1,301 infants and children, who developed SAM and were admitted to the three referral hospitals of the Amhara region. Data were extracted using a data extraction checklist. The binary logistic regression analysis was employed to show an association between the dependent and independent variables. Multicollinearity was assessed using the variance inflation factor (VIF) and no problem was detected (overall VIF = 1.67). The presence of association was declared based on the p -value (≤0.05), and the adjusted odds ratio with its respective 95% confidence interval was used to report the direction, as well as the strength of association. Results. About 41.43% (95% CI: 38.78%–44.13%) of severely malnourished infants and children have developed anemia, of which around half (47%) of them were under six months old. Rural residence (AOR = 1.56 95% CI: 1.14–2.12) and HIV infection (AOR = 2.00 95% CI: 1.04–3.86) were significantly associated with higher odds of anemia. Furthermore, being exclusively breastfed (AOR = 0.57 95% CI 0.39–0.83) remarkably reduced the likelihood of anemia. Conclusions. This data confirms that anemia among severely malnourished infants and children is a public health problem in the Amhara region. Infants younger than six months were at a higher risk of anemia. Being a rural resident and contracting HIV infection have elevated the occurrence of anemia, whereas being exclusively breastfed decreased the risk. Therefore, the study gives an insight to policymakers and planners to strengthen the existing exclusive breastfeeding practice. Strategies being practiced to prevent HIV transmission and early detection, as well as treatment, should also be strengthened. Furthermore, mothers/caretakers of infants and children residing in the rural areas deserve special attention through delivering nutrition education.

Realization of exchange bias control with manipulation of interfacial frustration in magnetic complex oxide heterostructures

Publisher: American Physical Society (APS)

Date: 30-11-2021

DOI: 10.1103/PHYSREVB.104.174444

Engineering Photoresponse in Epitaxial BiFe0. 5Cr0. 5O3 Thin Films through Structural Distortion

Publisher: American Chemical Society (ACS)

Date: 16-08-2022

DOI: 10.1021/ACS.JPCC.2C04297

Tuning Phase Transition and Thermochromic Properties of Vanadium Dioxide Thin Films via Cobalt Doping

Publisher: American Chemical Society (ACS)

Date: 24-04-2022

DOI: 10.1021/ACSAMI.2C03113

Abstract: Vanadium dioxide (VO

Ferroelectric crystals with giant electro-optic property enabling ultracompact Q-switches

Publisher: American Association for the Advancement of Science (AAAS)

Date: 22-04-2022

DOI: 10.1126/SCIENCE.ABN7711

Abstract: Relaxor-lead titanate (PbTiO 3 ) crystals, which exhibit extremely high piezoelectricity, are believed to possess high electro-optic (EO) coefficients. However, the optical transparency of relaxor-PbTiO 3 crystals is severely reduced as a result of light scattering and reflection by domain walls, limiting electro-optic applications. Through synergistic design of a ferroelectric phase, crystal orientation, and poling technique, we successfully removed all light-scattering domain walls and achieved an extremely high transmittance of 99.6% in antireflection film–coated crystals, with an ultrahigh EO coefficient r 33 of 900 picometers per volt (pm V −1 ), times as high as that of conventionally used EO crystals. Using these crystals, we fabricated ultracompact EO Q-switches that require very low driving voltages, with superior performance to that of commercial Q-switches. Development of these materials is important for the portability and low driving voltage of EO devices.

Interface-Charge Induced Giant Electrocaloric Effect in Lead Free Ferroelectric Thin-Film Bilayers

Publisher: American Chemical Society (ACS)

Date: 26-12-2020

DOI: 10.1021/ACS.NANOLETT.9B04727

Abstract: Conventional refrigeration methods based on compression-expansion cycles of greenhouse gases are environmentally threatening and cannot be miniaturized. Electrocaloric effects driven by electric fields are especially well suited for implementation of built-in cooling in portable electronic devices. However, most known electrocaloric materials present poor cooling performances near room temperature, contain toxic substances, and require high electric fields. Here, we show that lead-free ferroelectric thin-film bilayers composed of (Bi

Large negative electrocaloric response induced by nanoscale phase transition in (Bi, Na)TiO3-based thin films

Publisher: AIP Publishing

Date: 27-02-2023

DOI: 10.1063/5.0139202

Abstract: Electrocaloric effect (ECE) offers an efficient and environmentally friendly route for solid-state cooling. Either positive or negative ECE could exhibit a large adiabatic temperature change (ΔT). Compared to the positive electrocaloric response, the investigation of negative ECE is lagging behind, largely due to the fact that its origin is still elusive. In this work, the negative ECE behavior of conventional ferroelectric thin films, namely 0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3 (BNBT), was studied. A remarkable ΔT of −26.1 K was acquired near 160 °C under a moderate electric field of 875 kV/cm, attributing to the ferroelectric phase transition in the polar nanoregions from rhombohedral (R3c) to tetragonal (P4bm), as confirmed by temperature-dependent dielectric permittivity, Raman spectra, and x-ray reciprocal space mapping. The BNBT thin film presents a high electrocaloric coefficient (ΔT/ΔE) of 0.0298 K cm kV−1, transcending that of the most reported negative electrocaloric response of thin films.

Glassy Magnetic Transitions and Accurate Estimation of Magnetocaloric Effect in Ni–Mn Heusler Alloys

Publisher: American Chemical Society (ACS)

Date: 02-09-2020

DOI: 10.1021/ACSAMI.0C11308

Single-Crystal-like Textured Growth of CoFe₂O₄ Thin Film on an Amorphous Substrate: A Self-Bilayer Approach

Publisher: American Chemical Society (ACS)

Date: 21-10-2020

DOI: 10.1021/ACSAELM.0C00716

A New Strategy for Large Dynamic Piezoelectric Responses in Lead‐Free Ferroelectrics: The Relaxor/Morphotropic Phase Boundary Crossover

Publisher: Wiley

Date: 06-09-2020

DOI: 10.1002/ADFM.202004641

Efficient Cocatalyst-Free Piezo-Photocatalytic Hydrogen Evolution of Defective BaTiO_3–x Nanoparticles from Seawater

Publisher: American Chemical Society (ACS)

Date: 13-01-2023

DOI: 10.1021/ACSSUSCHEMENG.2C06573

A reflection on recent efforts in optimization of cooling capacity of electrocaloric thin films

Publisher: AIP Publishing

Date: 09-2023

DOI: 10.1063/5.0165495

Ultrahigh Energy Storage Density in Glassy Ferroelectric Thin Films under Low Electric Field

Publisher: Wiley

Date: 18-09-2022

DOI: 10.1002/ADVS.202203926

Abstract: The current approach to achieving superior energy storage density in dielectrics is to increase their breakdown strength, which often incurs heat generation and unexpected insulation failures, greatly deteriorating the stability and lifetime of devices. Here, a strategy is proposed for enhancing recoverable energy storage density ( W r ) while maintaining a high energy storage efficiency ( η) in glassy ferroelectrics by creating super tetragonal (super‐T) nanostructures around morphotropic phase boundary (MPB) rather than exploiting the intensely strong electric fields. Accordingly, a giant W r of ≈86 J cm −3 concomitant with a high η of ≈81% is acquired under a moderate electric field (1.7 MV cm −1 ) in thin films having MPB composition, namely, 0.94(Bi, Na)TiO 3 ‐0.06BaTiO 3 (BNBT), where the local super‐T polar clusters (tetragonality ≈1.25) are stabilized by interphase strain. To the knowledge of the authors, the W r of the engineered BNBT thin films represents a new record among all the oxide perovskites under a similar strength of electric field to date. The phase field simulation results ascertain that the improved W r is attributed to the local strain heterogeneity and the large spontaneous polarization primarily is originated from the super‐T polar clusters. The findings in this work present a genuine opportunity to develop ultrahigh‐energy‐density thin‐film capacitors for low‐electric‐field‐driven nano/microelectronics.

Large Electrocaloric Effect in Nanostructure-Engineered (Bi, Na)TiO₃-Based Thin Films

Publisher: American Chemical Society (ACS)

Date: 16-11-2022

DOI: 10.1021/ACSAMI.2C14831

Abstract: Although the solid-state cooling technology based on electrocaloric response has been considered a promising refrigeration solution for microdevices, the mediocre dipolar entropy change Δ

New Degree of Freedom in Determining Superior Piezoelectricity at the Lead-Free Morphotropic Phase Boundary: The Invisible Ferroelectric Crossover

Publisher: American Chemical Society (ACS)

Date: 03-01-2022

DOI: 10.1021/ACSAMI.1C19856

Abstract: The morphotropic phase boundary (MPB) in lead-free ferroelectrics, starting from a quadruple point (QP), often displays large piezoelectric responses due to the flattened free-energy profiles. In this work, we found that the QP composition rendering most flattened energy profiles could also exhibit abnormally low piezoelectric constants in Hf-doped BaTiO

A generic strategy for preparation of TiO2/BixMyOz (M = W, Mo) heterojunctions with enhanced photocatalytic activities

Publisher: Elsevier BV

Date: 05-2019

DOI: 10.1016/J.APSUSC.2018.12.297

Effect of polarization fatigue on the electrocaloric effect of relaxor Pb0.92La0.08Zr0.65Ti0.35O3 thin film

Publisher: AIP Publishing

Date: 16-11-2020

DOI: 10.1063/5.0018741

Abstract: The electrocaloric effect represents an adiabatic temperature change or isothermal entropy change upon the application or removal of an external electric field. However, the effect of the repetitive bipolar/unipolar electric field on the electrocaloric effect in ferroelectrics is not well understood. In this work, the electrocaloric effect after both bipolar and unipolar electrical cycling in Pb0.92La0.08Zr0.65Ti0.35O3 relaxor thin films has been indirectly evaluated using the Maxwell relationship. It was found that at room temperature, the electrocaloric temperature change ΔT under higher electric fields decreases gradually from a positive value to a negative one with the increase in the bipolar/unipolar fatigue cycle number. Intriguingly, around the Curie temperature, the positive ΔT of the film after bipolar/unipolar cycling was found to decrease under low or intermediate electric fields, while it remains almost unchanged under high electric fields. This behavior is attributed to the pinning effect of defects caused by phase decomposition during both bipolar and unipolar fatigue. Note that the increase in polarization by temperature induced domain depinning close to room temperature after the fatigue process is manifested by using the Maxwell relation indirectly. Our work further reveals the origin of both the electrocaloric effect and ferroelectric electrical fatigue and is important for the applications of practical electrocaloric refrigerators.

Approaching Piezoelectric Response of Pb-Piezoelectrics in Hydrothermally Synthesized Bi_0.5(Na_1–xK_x)_0.5TiO₃ Nanotubes

Publisher: American Chemical Society (ACS)

Date: 29-05-2018

DOI: 10.1021/ACSAMI.8B06312

Abstract: A large piezoelectric coefficient of 76 pm/V along the diameter direction, approaching that of lead-based piezoelectrics, is observed in hydrothermally synthesized Pb-free Bi

Largely Enhanced Mobility in Trilayered LaAlO3/SrTiO3/LaAlO3 Heterostructures

Publisher: American Chemical Society (ACS)

Date: 31-05-2018

DOI: 10.1021/ACSAMI.7B11218

Abstract: LaAlO

High-Temperature Flexible Transparent Heater for Rapid Thermal Annealing of Thin Films

Publisher: American Physical Society (APS)

Date: 26-04-2022

DOI: 10.1103/PHYSREVAPPLIED.17.044049

Co–Al-substituted strontium hexaferrite for rare earth free permanent magnet and microwave absorber application

Publisher: IOP Publishing

Date: 19-10-2020

DOI: 10.1088/1361-6463/ABB9D5

Abstract: Permanent magnets (PMs) have tremendous demand because of their applicability in various electronic devices. Rare earth (RE) elements are the major component in fabricating these PMs. Tremendous research interest has been generated over the last decade to design the RE-free PMs because of the ever-increasing cost of REs and shortage of their supply. Hexagonal ferrites show incredible potential as RE-free magnets owing to their high coercivity and moderate saturation magnetization. In this work, we focused on improving the magnetic properties of Sr 0.8 Ca 0.2 Al x Co x Fe 12−2x O 19 hexagonal ferrites with respect to Co 2+ –Al 3+ co-substitution synthesized by the sonochemical method. Improved saturation magnetization of 64.4 emu g −1 , coercivity of 13.2 kOe, and a remnant ratio of 0.71 was achieved upon Co 2+ –Al 3+ substitution. The prepared materials were also tested for microwave absorption characteristics, where a maximum reflection loss of −35.4 dB at 12.36 GHz was obtained. Results were discussed in light of the synthesis method, Co 2+ –Al 3+ substitution, and electrical properties. Such improvement in the electromagnetic properties make these ferrites suitable for use as RE-free PMs and microwave absorbers.

Highly Efficient Visible Light Photocatalytic Activities in Self-Assembled Metastable TiO₂/Bi₄MoO₉ Heterojunctions

Publisher: Wiley

Date: 06-08-2018

DOI: 10.1002/ADMI.201800844

Vortex dynamics in amorphous MoSi superconducting thin films

Publisher: IOP Publishing

Date: 09-11-2021

DOI: 10.1088/1361-6668/AC2EB0

Abstract: Vortex dynamics in superconductors have received a great deal of attention from both fundamental and applied researchers over the past few decades. Because of their critical role in the energy relaxation process of type-II superconductors, vortex dynamics have been deemed a key factor for the emerging superconducting devices, but the effect of irradiation on vortex dynamics remains unclear. With the support of electrical transport measurements under external magnetic fields and irradiation, the photon effect on vortex dynamics in amorphous MoSi ( a -MoSi) superconducting thin films is investigated in this work. The magnetic-field-dependent critical vortex velocity v * derived from the Larkin–Ovchinnikov (LO) model is not significantly affected by irradiation. However, vortex depinning is found to be enhanced by photon-induced reduction in the potential barrier, which mitigates the adverse effect of film inhomogeneity on superconductivity in the a -MoSi thin films. A thorough understanding of the vortex dynamics in a -MoSi thin films under the effect of external stimuli is of paramount importance for both further fundamental research in this area and the optimization of future superconducting devices.

Lead zirconate titanate ceramics with aligned crystallite grains

Publisher: American Association for the Advancement of Science (AAAS)

Date: 07-04-2023

DOI: 10.1126/SCIENCE.ADF6161

Abstract: The piezoelectric properties of lead zirconate titanate [Pb(Zr,Ti)O 3 or PZT] ceramics could be enhanced by fabricating textured ceramics that would align the crystal grains along specific orientations. We present a seed-passivated texturing process to fabricate textured PZT ceramics by using newly developed Ba(Zr,Ti)O 3 microplatelet templates. This process not only ensures the template-induced grain growth in titanium-rich PZT layers but also facilitates desired composition through interlayer diffusion of zirconium and titanium. We successfully prepared textured PZT ceramics with outstanding properties, including Curie temperatures of 360°C, piezoelectric coefficients d 33 of 760 picocoulombs per newton and g 33 of 100 millivolt meters per newton, and electromechanical couplings k 33 of 0.85. This study addresses the challenge of fabricating textured rhombohedral PZT ceramics by suppressing the otherwise severe chemical reaction between PZT powder and titanate templates.

UNSW Sydney

Location: Australia

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UNSW Australia

Location: Australia

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University Of Tamania

Location: Australia

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Linkage Infrastructure, Equipment And Facilities - Grant ID: LE230100024

Start Date: 2023

End Date: 12-2023

Amount: $909,754.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP140104373

Start Date: 2014

End Date: 12-2016

Amount: $400,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100106

Start Date: 07-2013

End Date: 02-2016

Amount: $340,000.00

Funder: Australian Research Council

ARC Future Fellowships - Grant ID: FT180100541

Start Date: 11-2018

End Date: 10-2023

Amount: $873,125.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP170103514

Start Date: 2017

End Date: 12-2020

Amount: $300,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP220103229

Start Date: 2022

End Date: 06-2025

Amount: $510,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP110104629

Start Date: 2011

End Date: 06-2016

Amount: $210,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE220100114

Start Date: 07-2022

End Date: 12-2023

Amount: $1,040,375.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE160100199

Start Date: 06-2016

End Date: 06-2018

Amount: $367,900.00

Funder: Australian Research Council