Anisotropy of electronic stopping power in graphite

Abstract

The rate of energy transfer from ion projectiles onto the electrons of a solid target is hard to determine experimentally in the velocity regime between the adiabatic limit and the Bragg peak. First-principles simulations have lately offered relevant new insights and quantitative information for prototypical homogeneous materials. Here we study the influence of structural anisotropy on electronic stopping power with time-dependent density functional theory simulations of a hydrogen projectile in graphite. The projectile traveled at a range of angles and impact parameters for velocities between 0.1 and 1.4 a.u., and the electronic stopping power was calculated for each simulation. After validation with average experimental data, the anisotropic crystal structure was found to have a strong influence on the stopping power, with a difference between simulations parallel and perpendicular to the graphite plane of up to 25%, more anisotropic than expected based on previous work. The velocity dependence at low velocity displays clear linear behavior in general, except for projectiles traveling perpendicular to graphitic layers, for which a threshold-like behavior is obtained. For projectiles traveling along graphitic planes metallic behaviour is observed with a change of slope when the projectile velocity reaches the Fermi velocity of the electrons.

arXiv comment8 pages, 6 figures

References in corpus (11)

• The SIESTA method for ab initio order-N materials simulation
• Efficient index handling of multidimensional periodic boundary conditions
• Numerical atomic orbitals for linear scaling
• Calculation of the optical response of C60 and Na8 using time-dependent density functional theory and local orbitals
• Electronic stopping power in insulators from first principles
• Electronic stopping power in gold: The role of d electrons and the H/He anomaly
• Core electrons in the electronic stopping of heavy ions
• Examining real-time TDDFT non-equilibrium simulations for the calculation of electronic stopping power
• Electronic stopping power in a narrow band gap semiconductor from first principles
• Quantum mechanics in an evolving Hilbert space
• Electronic stopping and proton dynamics in InP, GaP, and In${}_{0.5}$Ga${}_{0.5}$P from first principles

Cited by in corpus (8)

• SIESTA: recent developments and applications
• Disparate energy scaling of trajectory-dependent electronic excitations for slow protons and He ions
• Anomalous stopping and charge transfer in proton-irradiated graphene
• Trajectory-dependent electronic excitations by light and heavy ions around and below the Bohr velocity
• Ab initio electronic stopping power for protons in Ga${}_{0.5}$In${}_{0.5}$P/GaAs/Ge triple-junction solar cells for space applications
• Ehrenfest dynamics with localized atomic-orbital basis sets within the projector augmented-wave method
• Numerical integration of quantum time evolution in a curved manifold
• Contrast modes in a 3D ion transmission approach at keV energies