First-principles study of the threshold effect in the electronic stopping power of LiF and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mtext>SiO</mml:mtext><mml:mn>2</mml:mn></mml:msub></mml:math>for low-velocity protons and helium ions

Mao, Fei; Zhang, Chao; Dai, Jingjie; Zhang, Feng-Shou

doi:10.1103/physreva.89.022707

Cited by 20 publications

(15 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…TDDFT complements a variety of other atomistic and non-atomistic techniques with adjustable parameters [7,20,21]. Based on our simulation results and a quantum mechanical band-structure picture, we propose a coupled-rateequation model that explains the electronic stopping mechanisms in this regime.It has been suggested that there is a threshold velocity below which a light projectile (such as a proton) moving through a wide-band-gap insulator (such as LiF) is unable to exchange sufficient energy to excite electrons across the band gap [5,22]. The electronic stopping would be strictly zero below this threshold.…”

mentioning

confidence: 99%

Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State

et al. 2016

View full text Add to dashboard Cite

We use time-dependent density functional theory to study self-irradiated Si. We calculate the electronic stopping power of Si in Si by evaluating the energy transferred to the electrons per unit path length by an ion of kinetic energy from 1 eV to 100 keV moving through the host. Electronic stopping is found to be significant below the threshold velocity normally identified with transitions across the band gap. A structured crossover at low velocity exists in place of a hard threshold. An analysis of the time dependence of the transition rates using coupled linear rate equations enables one of the excitation mechanisms to be clearly identified: a defect state induced in the gap by the moving ion acts like an elevator and carries electrons across the band gap.

show abstract

mentioning

confidence: 99%

Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State

et al. 2016

View full text Add to dashboard Cite

show abstract

“…For insulators, the electron excitations are suppressed due to a minimum excitation energy, the energy band gap of these materials plays a fundamental role. The interaction of low energy protons, in these cases, was described by invoking the creation of negative ions and charge interchange via electron promotion (29)(30)(31)(32)(33).…”

Section: Resultsmentioning

confidence: 99%

Proton energy loss in multilayer graphene and carbon nanotubes

Uribe

Mery

Fierro

et al. 2018

Radiation Effects and Defects in Solids

View full text Add to dashboard Cite

Results of a study of electronic energy loss of low keV protons interacting with multilayer graphene targets are presented. Proton energy loss shows an unexpectedly high value as compared with measurements in amorphous carbon and carbon nanotubes. Furthermore, we observe a classical linear behavior of the energy loss with the ion velocity but with an apparent velocity threshold around 0.1 a.u., which is not observed in other carbon allotropes. This suggests low dimensionality effects which can be due to the extraordinary graphene properties.

show abstract

“…in LiF under grazing incidence [24]. Recent theoretical and experimental research managed to measure velocities in extremely low velocity regime (v ≤ 0.1 a.u) displaying a clear velocity threshold [20,[25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Ab initioelectronic stopping power and threshold effect of channeled slow light ions inHfO2

Wang

Liao

et al. 2017

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

We present ab initio study of the electronic stopping power of protons and helium ions in an insulating material, HfO2. The calculations are carried out in channeling conditions with different impact parameters by employing Ehrenfest dynamics and real-time, time-dependent density functional theory. The satisfactory comparison with available experiments demonstrates that this approach provides an accurate description of electronic stopping power. The velocity-proportional stopping power is predicted for protons and helium ions in the low energy region, which conforms the linear response theory. Due to the existence of wide band gap, a threshold effect in extremely low velocity regime below excitation is expected. For protons, the threshold velocity is observable, while it does not appear in helium ions case. This indicates the existence of extra energy loss channels beyond the electron-hole pair excitation when helium ions are moving through the crystal. To analyze it, we checked the charge state of the moving projectiles and an explicit charge exchange behavior between the ions and host atoms is found. The missing threshold effect for helium ions is attributed to the charge transfer, which also contributes to energy loss of the ion.

show abstract

First-principles study of the threshold effect in the electronic stopping power of LiF andSiO2for low-velocity protons and helium ions

Cited by 20 publications

References 41 publications

Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State

Electron Elevator: Excitations across the Band Gap via a Dynamical Gap State

Proton energy loss in multilayer graphene and carbon nanotubes

Ab initioelectronic stopping power and threshold effect of channeled slow light ions inHfO2

Contact Info

Product

Resources

About