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Journal of Physics D: Applied Physics - latest papers

Latest articles for Journal of Physics D: Applied Physics

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  • A global kinetics approach to determine relative reactivity of unsaturated volatile organic compounds toward non-thermal plasma components in air
    An experimental approach is proposed to determine the relative reactivity of volatile organic compounds (VOCs) in air relative to the components of non-equilibrium discharge plasma. The experimental data were processed using the global kinetics method. It is shown that the relative reactivity of VOCs is a parameter that is weakly dependent on the plasma generation method, while the energy consumption for removing an impurity molecule varies significantly depending on the specific setup and plasma generation method. Using a mixture of unsaturated compounds: methyl methacrylate and styrene, it has been shown that the main concentration dependencies are satisfactorily described using a single formal reagent as a set of active plasma components. It was shown on a corona discharge of 20–40 ns duration and 100–150 kV voltage that the relative reactivity of methyl methacrylate relative to styrene is 0.43–0.45. The correctness of the assumptions made was checked by solving forward and backward kinetic problems and checking their correspondence to the experiment. The influence of oxygen content and additives on the relative reactivity and energy consumption is shown. The relative reactivity of other unsaturated compounds in relation to the components of the corona discharge plasma was determined: styrene, methyl methacrylate, α-methylstyrene, and vinyl acetate, which are expressed as 1.0:0.43:1.63:0.21, respectively. The presented methodology enables the acquisition of statistically robust data applicable across diverse scenarios. Ultimately, this experimental framework establishes a unified methodology for investigating VOC abatement. This approach significantly enhances the transferability of laboratory-scale data to industrial reactor design and scale-up procedures.

  • Prediction of lightning impulse insulation performance of C4F7N/CO2 gas mixtures with different mixing ratios
    The use of , a gas with an extremely high global warming potential, has been increasingly restricted, while gas mixtures are regarded as one of the most promising environmentally friendly insulating media for high-voltage applications and have already been employed in eco-friendly gas-insulated equipment. Lightning impulse insulation performance is an important criterion for evaluating the dielectric performance of novel gas-insulated equipment. However, fully relying on lightning impulse tests to determine the breakdown characteristics and the effects of key influencing factors is time-consuming, which significantly hinders the development of such equipment. In this work, a streamer discharge model of mixtures under lightning impulse voltage across a 10 mm gap was developed. The effects of the mixing ratio and voltage polarity on streamer discharge were investigated, and a method for predicting lightning impulse insulation performance based on the streamer inception voltage and breakdown voltage was proposed. The results show that increasing the content enhances the electronegativity of the mixture and suppresses electron-impact ionization reactions, thereby improving its lightning impulse insulation performance. Moreover, the streamer discharge model exhibits good predictive performance. Under positive polarity, the prediction errors for the lightning impulse insulation performance of mixtures containing 3.5% and 6% at pressures of 0.5–0.8 MPa are all below 5%. Exploratory estimates based on the model further indicate a pronounced polarity effect in the predicted 50% lightning impulse voltage under negative polarity. Using the same fitted parameters, the predicted 50% lightning impulse voltages of the mixture containing 3.5% increase by 12.9%, 14.3%, 10.6%, and 5.2% at 0.5, 0.6, 0.7, and 0.8 MPa, respectively, compared with those under positive polarity. For the mixture containing 6% , the corresponding increases are 9.5%, 21.1%, 26.4%, and 17.7%, respectively.

  • CORRIGENDUM: Experimental studies on shock wave and vapor bubbles generated by high-energy laser ablation of titanium foil in water (2025 J. Phys. D: Appl. Phys. 58 255202)
  • Electrothermal analysis of an infinite conducting material with a planar crack
    Current-assisted processing has increasingly been used to tune material microstructures and to heal structural flaws. At the heart of this technique is the interaction between electric current and the material, which induces localized heating, enhances atomic migration, and activates related physicochemical processes. In this work, we analyze the flow of electric current in an infinite conducting medium containing a planar crack, specifically a Griffith-like crack and a penny-shaped crack, and the resulting steady-state, current-induced temperature field. Closed-form solutions for both the electric field and the steady-state temperature field are obtained. The electric field exhibits a square-root singularity at the crack tip or edge; however, no corresponding singularity arises in the steady-state temperature field at the same location that could cause local melting and crack healing. It is the transient and singular behavior of Joule heat at the crack tip or edge that can generate local melting and initiate the healing process. To quantify this behavior, we introduce a local melting zone surrounding the crack tip or edge and derive an approximate expression for its size under the assumption that the relevant material constants, including the transfer rate of heat, are temperature-independent. The extent of this melting zone scales with both the input power and the duration of electric-current flow. Increasing the input power and the current-flow time likely enhances the effectiveness of current-assisted healing of structural flaws in metallic materials.

  • Temperature and thickness dependence of Gilbert damping parameter of CoFe thin films: atomistic study
    We have performed atomistic spin-dynamics simulations to investigate how temperature and thickness affect the Gilbert damping parameter of the ferromagnetic CoFe thin film and its interface with MgO. Enhanced interfacial damping is considered at the interface compared with the bulk-like layers due to high spin–orbit coupling. Our results reveal a strong dependence of Gilbert damping on thickness, consistent with experimental results for soft magnets. The enhancement of Gilbert damping at the interface was found to be greater than in bulk-like behavior. The effect of temperature was studied by gradually varying thermal fluctuations from 0 K to 350 K. No significant change was observed. Interestingly, we have also extracted the surface and bulk damping from the Gilbert damping parameter for a given temperature range. The increasing trend in bulk damping with temperature suggests the induced reorientation of spins at high temperatures. Also, the decreasing trend in surface damping is attributed to diminishing spin coherence, which blurs the relative contrast of anisotropy variations. Consequently, this suppresses the scattering and reduces the surface damping. This statistical variation in Gilbert damping with thickness and temperature, alongside information on bulk and surface damping, is important for understanding the dynamic properties of magnetic tunnel junctions and for establishing an intrinsic limit on reliability in small magnetic nanodevices, where control over dynamic response is important.