2026-06-27T15:24:34Zhttps://docta.ucm.es/rest/oai/request
oai:docta.ucm.es:20.500.14352/732612025-04-22T14:41:41Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense author Schell, Juliana author Zyabkin, Dmitry author Bharuth-Ram, Krish author Gonçalves, Joao N. author Díaz-Guerra Viejo, Carlos author Gunnlaugsson, Haraldur P. author Tarazaga Martín-Luengo, Aitana author Schaaf, Peter author Bonanni, Alberta author Masenda, Hilary author Qi, Bingqui 2023-06-22T12:51:30Z 2023-06-22T12:51:30Z 2022-07 2073-4352 10.3390/cryst12070942 https://hdl.handle.net/20.500.14352/73261 http://dx.doi.org/10.3390/cryst12070942 https://www.mdpi.com/ Van der Waals alpha-MoO_(3) samples offer awide range of attractive catalytic, electronic, and optical properties. We present herein an emission Mossbauer spectroscopy (eMS) study of the electric-field gradient (EFG) anisotropy in crystalline free-standing alpha-MoO_(3) samples. Although alpha-MoO3 is a twodimensional (2D) material, scanning electron microscopy shows that the crystals are 0.5-5-mu m thick. The combination of X-ray diffraction and micro-Raman spectroscopy, performed after sample preparation, provided evidence of the phase purity and crystal quality of the samples. The eMS measurements were conducted following the implantation of (57)^Mn (t(1/ 2) = 1.5 min), which decays to the (57)^Fe, 14.4 keV Mossbauer state. The eMS spectra of the samples are dominated by a paramagnetic doublet (D1) with an angular dependence, pointing to the Fe^(2+) probe ions being in a crystalline environment. It is attributed to an asymmetric EFG at the eMS probe site originating from strong in-plane covalent bonds and weak out-of-plane van derWaals interactions in the 2D material. Moreover, a second broad component, D2, can be assigned to Fe^(3+) defects that are dynamically generated during the online measurements. The results are compared to ab initio simulations and are discussed in terms of the in-plane and out-of-plane interactions in the system eng Atribución 3.0 España Anisotropy of the electric field gradient in two-dimensional alpha-MoO_(3) investigated by (57)^Mn((57)^Fe) emission mossbauer spectroscopy journal article URL https://docta.ucm.es/bitstreams/b6ce636d-ce82-4da1-9101-35203975498c/download File MD5 12b7d619260493ec5bdfa9fefea4cf22 2806346 application/pdf Díaz-Guerra,C 25 OA+CC.pdf URL https://docta.ucm.es/bitstreams/b072ac6a-85d7-463d-88a4-34e446950d62/download File MD5 432f8e46d96f3b13064f114753c6757c 57402 text/plain Díaz-Guerra,C 25 OA+CC.pdf.txt