In this work the kinetics of the charge ordering in magnetite (Fe3O4) below the Verwey transition temperature TV is investigated in time and energy domain. After excitation by a one-second voltage pulse to destruct the charge-ordered state below TV, an alternating current (AC) is used to perturb its recovery process. Upon warming up to above a temperature T(r)(< TV) the charge order recovers despite the ac perturbation, because the temperature-dependent relaxation time becomes shorter than the polarity change of the ac. From the frequency dependence of T(r)(f), an activation energy of ΔE = 126 meV is extracted. Below Tr the real part of the ac conductance Greal follows the relation Greal ∼ f(α) with α = 0.98 ± 0.18, suggesting that the charge reordering is driven by correlated hopping transport. The relaxation time τ = 1/f(T(r)) of the charge-ordered state is determined for temperatures between 70 and 98 K and is extrapolated to τ(TV) = 1.6 ms, continuously slowing down its dynamics as the temperature is decreased.

Download full-text PDF

Source
http://dx.doi.org/10.1088/0953-8984/26/47/472202DOI Listing

Publication Analysis

Top Keywords

kinetics charge
8
charge ordering
8
ordering magnetite
8
charge-ordered state
8
relaxation time
8
magnetite verwey
4
temperature
4
verwey temperature
4
temperature work
4
work kinetics
4

Similar Publications

Synthesis of zeolite from rice husk ash and kaolinite clay for the removal of methylene blue from aqueous solution.

Heliyon

January 2025

Department of Chemistry, School of Physical Sciences, College of Agriculture and Natural Sciences, University of Cape Coast, Cape Coast, Ghana.

Zeolite was successfully synthesized using a mixture of kaolinite clay (which served as the alumina source) and rice husk ash (silica source). The aim of this work was to synthesize highly efficient zelolite to remove methyle blue dye from aqueous solution. The synthesized adsorbent was characterised using Fourier Transform Infrared (FTIR) spectroscopy, powder x-ray diffraction (PXRD) analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and pH at the point of zero charge (pHpzc).

View Article and Find Full Text PDF

Amorphization Stabilizes Te-based Aqueous Batteries via Confining Free Water.

Angew Chem Int Ed Engl

January 2025

Fudan University, Laboratory of Advanced Materials, Shanghai, 200433, Shanghai, CHINA.

Tellurium (Te), with its rich valence states (-2 to +6), could endow aqueous batteries with potentially high specific capacity. However, achieving complete and stable hypervalent Te0/Te4+ electrochemistry in an aqueous environment poses significant challenges, owing to the sluggish reduction kinetics, the easy dissolution of Te4+ species, and a controversial energy storage mechanism. Herein, for the first time, we demonstrate an amorphous strategy for robust aqueous TeO2/Te electrochemistry.

View Article and Find Full Text PDF

2D materials feature large specific surface areas and abundant active sites, showing great potential in energy storage and conversion. However, the dense, stacked structure severely restricts its practical application. Inspired by the structure of bamboo in nature, hollow interior and porous exterior wall, hollow MXene aerogel fiber (HA-TiCT fiber) is proposed.

View Article and Find Full Text PDF

Recent Advances in Polymorphism of Organic Solar Cells.

Small

January 2025

School of Electronics and Information, Northwestern Polytechnical University, 1 Dongxiang Road, Xi'an, 710129, China.

As organic solar cells (OSCs) achieve notable advancements, a significant consensus has been highlighted that the device performance is intricately linked to the active layer morphology. With conjugated molecules being widely employed, intermolecular interactions exert substantial influence over the aggregation state and morphology formation, resulting in distinct molecular packing motifs, also known as polymorphism. This phenomenon is closely associated with processing conditions and exerts a profound impact on functional properties.

View Article and Find Full Text PDF

Aim: Despite dysfunctional vasoactive intestinal polypeptide-positive interneurons (VIP-INs) being linked to the emergence of neurodevelopmental disorders, the temporal profile of VIP-IN functional maturation and cortical network integration remains unclear.

Methods: Postnatal VIP-IN development was traced with patch clamp experiments in the somatosensory cortex of Vip-IRES-cre x tdTomato mice. Age groups were chosen during barrel field formation, before and after activation of main sensory inputs, and in adult animals (postnatal days (P) P3-4, P8-10, P14-16, and P30-36).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!