Dr Alejandro Trejo Baños

@article{BERMEOCAMPOS2023157481,

title = {Surface morphology effects on the mechanical and electronic properties of halogenated porous 3C-SiC: A DFT study},

author = {R. Bermeo-Campos and K. Madrigal-Carrillo and S. E. Perez-Figueroa and M. Calvino and A. Trejo and F. Salazar and A. Miranda and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S0169433223011595},

doi = {https://doi.org/10.1016/j.apsusc.2023.157481},

issn = {0169-4332},

year  = {2023},

date = {2023-01-01},

journal = {Applied Surface Science},

volume = {631},

pages = {157481},

abstract = {Silicon carbide nanostructures have been widely studied due to their potential technological applications. However, the theoretical characterization, especially the effect of the surface on the mechanical properties of this material is still underexplored. In this work, we report the electronic and mechanical properties of 3C-SiC nanopores with different pore surfaces and different passivation schemes using a density functional theory approach and the supercell technique. The nanopores were modeled by removing columns of atoms in the [001] direction, thus creating four types of pores, two with an Only C or Si pore and two with a C or Si-Rich pore surface. All surfaces were passivated with hydrogen, then some atoms of H were replaced with fluorine and chlorine. Results show that pores with a higher concentration of C on the surface have a larger bandgap compared with the Si cases. Moreover, only a few changes can be observed due to passivation. For the mechanical properties the Bulk and Young’s modulus were calculated and show that the Only C structures were the most brittle and, for almost all the pores, the H + Cl passivation improve the Bulk modulus.},

keywords = {DFT, electronic properties, Halogens, Mechanical properties, Porous SiC},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/jcc.26421,

title = {Effects of lithium on the electronic properties of porous Ge as anode material for batteries},

author = {Akari Narayama Sosa and Israel Gonz\'{a}lez and Alejandro Trejo and \'{A}lvaro Miranda and Fernando Salazar and Miguel Cruz-Irisson},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/jcc.26421},

doi = {https://doi.org/10.1002/jcc.26421},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Computational Chemistry},

volume = {41},

number = {31},

pages = {2653-2662},

abstract = {Abstract Recently, the need of improvement of energy storage has led to the development of Lithium batteries with porous materials as electrodes. Porous Germanium (pGe) has shown promise for the development of new generation Li-ion batteries due to its excellent electronic, and chemical properties, however, the effect of lithium in its properties has not been studied extensively. In this contribution, the effect of surface and interstitial Li on the electronic properties of pGe was studied using a first-principles density functional theory scheme. The porous structures were modeled by removing columns of atoms in the [001] direction and the surface dangling bonds were passivated with H atoms, and then replaced with Li atoms. Also, the effect of a single interstitial Li in the Ge was analyzed. The transition state and the diffusion barrier of the Li in the Ge structure were studied using a quadratic synchronous transit scheme.},

keywords = {Density Functional Theory, electronic properties, Li-ion batteries, porous germanium, transition state},

pubstate = {published},

tppubtype = {article}

}

@article{DESANTIAGO2019438,

title = {Lithiation effects on the structural and electronic properties of Si nanowires as a potential anode material},

author = {F. De Santiago and J. E. Gonz\'{a}lez and A. Miranda and A. Trejo and F. Salazar and L. A. P\'{e}rez and M. Cruz-Irisson},

url = {https://www.sciencedirect.com/science/article/pii/S2405829718313254},

doi = {https://doi.org/10.1016/j.ensm.2019.04.023},

issn = {2405-8297},

year  = {2019},

date = {2019-01-01},

journal = {Energy Storage Materials},

volume = {20},

pages = {438-445},

abstract = {The need for better energy-storage materials has attracted much attention to the development of Li-ion battery electrodes. Si nanowires have been considered as alternative electrodes, however the effects of Li on their electronic band gap and mechanical properties have been scarcely studied. In this work, a density functional study of the electronic and mechanical properties of hydrogen passivated silicon nanowires (H-SiNWs) grown along the [001] direction is presented. The Li atoms are gradually inserted at interstitial positions or replacing surface H atoms. The results show that, for surface-lithiated H-SiNWs, the semiconducting band gap decreases when the concentration of Li atoms increases; whereas the H-SiNWs become metallic even with the addition of only one interstitial Li atom. The formation energy diminishes with the concentration of Li atoms for surface-lithiated H-SiNWs, whereas the contrary behavior is found in the interstitial-lithiated H-SiNWs. Furthermore, for the surface-lithiation case, the Li binding energy reveals the existence of SiLi bonds, whereas for the interstitial-lithiation case, the Li binding energy increases when the Li grows up to a critical concentration, where some SiSi bonds break. Finally, for the case of surface-lithiation, the Young's modulus (Y) increases with the concentration of Li, whereas for the interstitial-lithiation case, Y suffers a sudden diminution at a certain Li concentration due to the large internal mechanical stresses within the nanowire structure. These results should be considered when regarding H-SiNWs as potential electrodes in Li-ion battery anodes.},

keywords = {electronic properties, Li batteries, Silicon nanowires, Young's modulus},

pubstate = {published},

tppubtype = {article}

}

@article{PILO2016110,

title = {Effect of the transition metal ratio on bulk and thin slab double perovskite Sr2FeMoO6},

author = {J. Pilo and A. Trejo and E. Carvajal and R. Oviedo-Roa and M. Cruz-Irisson and O. Navarro},

url = {https://www.sciencedirect.com/science/article/pii/S0167931716302283},

doi = {https://doi.org/10.1016/j.mee.2016.04.026},

issn = {0167-9317},

year  = {2016},

date = {2016-01-01},

journal = {Microelectronic Engineering},

volume = {162},

pages = {110-113},

abstract = {Double perovskites are promising materials for multiple applications on microelectronics, specially on magnetic devices development. Perhaps the most interesting one is the double perovskite Sr2FeMoO6 since its magnetic properties differ from that of other related simple perovskites: SrFeO3 and SrMoO3. In this work the evolution of the electronic properties and the magnetic moment distribution as a function of the Fe/Mo ratio in bulk and a thin slab of Sr2FeMoO6 was studied. The thin slab was constructed keeping free surfaces parallel to the (001) crystalline planes with different thickness and compositions. All calculations were made in the Density Functional Theory scheme in the Generalized Gradient Approximation, using the Perdew-Burke-Ernzerhof functional, as implemented in the DMol3 code. After being geometry optimized, the electronic Density of States and band structure were calculated, as well as the magnetic moment distribution, for each modeled system. Essential results are as follows: for the bulk cases it was found that half-metallic behavior which characterizes the stoichiometric double perovskite changes if the compound becomes molybdenum or iron rich; for the slab is remarkable the induction of magnetic moments, owed to the corresponding to iron atoms, over their neighbor atoms.},

keywords = {Density Functional Theory, electronic properties, Magnetic properties, Perovskites, Thin slabs},

pubstate = {published},

tppubtype = {article}

}