Magnetic Force Microscopy Study of Multiscale Ion-Implanted Platinum in Silica Glass, Recorded by an Ultrafast Two-Wave Mixing Configuration

Torres-Torres, D.; Bornacelli, J.; Vega-Becerra, O.; Garay-Tapia, A.M.; Aguirre-Tostado, F. S.; Torres-Torres, C.; Oliver, A.

doi:10.1017/s1431927619015204

Cited by 4 publications

(2 citation statements)

References 34 publications

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“…Besides, silica has a wide range of optical transmission from UV to near-infrared frequencies depending on their purity and composition that allows embedded nanometals to be potentially used in magneto-optical basic and applied research. Recently, we have reported a magnetic response from Pt nano/micro particles embedded in silica and morphological modified by ultrafast laser pulses [18]. To the best of our knowledge, this is the first report of ferromagnetic properties of Pt particles embedded in an inorganic matrix by ion-implantation.…”

Section: Introductionmentioning

confidence: 71%

Enhanced ultrafast optomagnetic effects in room-temperature ferromagnetic Pt nanoclusters embedded in silica by ion implantation

et al. 2020

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Ferromagnetic-like behavior at room temperature (300 K) was observed in Pt particles embedded in ion-implanted silica matrices. Results in samples integrated by ultra-small photoluminescent Pt clusters (<2 nm) were compared with samples containing exclusively larger plasmonic Pt nanoparticles (>3 nm). The ferromagnetic behavior coexists simultaneously with a diamagnetic response. Enhanced diamagnetic response of one order of magnitude was observed compared to typical diamagnetism in pure silica, and it is increased with the mean diameter of the Pt particles. Besides, a larger sensitivity to an external field was observed in the ferromagnetic response of the nanostructures with a characteristic saturation at 20 kOe. This ferromagnetic behavior was only observed in the samples with nucleated Pt particles. The magnitude of the saturation magnetization shows up to a fivefold increase in the samples with smaller particle size and larger particle density. Saturation magnetization was observed between 3–15 × 10−4 emu g−1, with remanent magnetization of 0.2–0.6 × 10−4emu g−1, measured at 300 K. Coercitive fields also decrease in samples with smaller size and particles density, with values of 114 and 300 Oe. At lower temperatures (5 K) the saturation magnetization increases, as it would be expected from a ferromagnetic state. Optomagnetic response was studied by inverse Faraday effects and induced photomagnetization with circular polarized picosecond pulsed light at 1064 nm wavelength. Results showed that samples with a stronger ferromagnetic response exhibit larger Faraday rotation up to 5.3 × 103deg cm−1 by light excitations with irradiances between 50 and 180 GW cm−2. These findings have immediate applications in multifunctional solid-state magneto-optical devices such as optical isolators, high-data storage devices and ultrafast all-optical switching of magnetization.

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Section: Introductionmentioning

confidence: 71%

Enhanced ultrafast optomagnetic effects in room-temperature ferromagnetic Pt nanoclusters embedded in silica by ion implantation

et al. 2020

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“…The specimens employed in this study were inorganic nanocrystals deposited on a thin carbon film. Analysis of nanocrystals is definitely useful by itself, but we plan to employ 4D-STEM/PNBD method also in characterization of other important types of samples: polymer nanocomposites (such as magnetic polymer microspheres filled with iron oxide nanoparticles [38]), inorganic nanoparticles in amorphous matrices (such as platinum nanoparticles in silica glass [39]), and biological samples containing nanocrystalline materials (such as calcite-precipitating bacteria [40] or biological tissues with nanocrystalline markers [41]). In these systems, a standard analysis of the inorganic nanoparticles by TEM/SAED is very difficult, as the majority of scattered electrons come from the amorphous matrix and diffractions from the nanocrystals are almost lost in the high background.…”

Section: Further Applications Of 4d-stem/pnbd Methodsmentioning

confidence: 99%

High Resolution Powder Electron Diffraction in Scanning Electron Microscopy

et al. 2021

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A modern scanning electron microscope equipped with a pixelated detector of transmitted electrons can record a four-dimensional (4D) dataset containing a two-dimensional (2D) array of 2D nanobeam electron diffraction patterns; this is known as a four-dimensional scanning transmission electron microscopy (4D-STEM). In this work, we introduce a new version of our method called 4D-STEM/PNBD (powder nanobeam diffraction), which yields high-resolution powder diffractograms, whose quality is fully comparable to standard TEM/SAED (selected-area electron diffraction) patterns. Our method converts a complex 4D-STEM dataset measured on a nanocrystalline material to a single 2D powder electron diffractogram, which is easy to process with standard software. The original version of 4D-STEM/PNBD method, which suffered from low resolution, was improved in three important areas: (i) an optimized data collection protocol enables the experimental determination of the point spread function (PSF) of the primary electron beam, (ii) an improved data processing combines an entropy-based filtering of the whole dataset with a PSF-deconvolution of the individual 2D diffractograms and (iii) completely re-written software automates all calculations and requires just a minimal user input. The new method was applied to Au, TbF3 and TiO2 nanocrystals and the resolution of the 4D-STEM/PNBD diffractograms was even slightly better than that of TEM/SAED.

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