Self-assembly of silicon nanowires studied by advanced transmission electron microscopy

• Marta Agati,
• Guillaume Amiard,
• Vincent Le Borgne,
• Paola Castrucci,
• Richard Dolbec,
• Maurizio De Crescenzi,
• My Alì El Khakani and
• Simona Boninelli

Beilstein J. Nanotechnol. 2017, 8, 440–445, doi:10.3762/bjnano.8.47

• possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor–liquid–solid (VLS) mechanism

• within the plasma reactor. Both the STEM tomography and STEM-EDX analysis contributed to gain further insight into the self-assembly process. In the long-term, this approach might be used to optimize the synthesis of VLS-grown SiNWs via ICP as a competitive technique to the well-established bottom-up

• annular dark field (HAADF) in STEM associated with ET has been confirmed as the most appropriate mode to image crystals, since it meets the projection requirement, associating the contrast to the atomic number [6]. By combining the HAADF and ET techniques along with energy dispersive X-ray (EDX

Role of oxygen in wetting of copper nanoparticles on silicon surfaces at elevated temperature

• Tapas Ghosh and
• Biswarup Satpati

Beilstein J. Nanotechnol. 2017, 8, 425–433, doi:10.3762/bjnano.8.45

• spectroscopy (EDX) and X-ray diffraction (XRD) analysis shows that the thermal oxidation of the copper nanoparticles and formation of cupric oxide (CuO) on silicon surfaces leads to wetting rather than agglomeration. In contrast, agglomeration has been observed when copper nanoparticles were annealed in a

• field TEM image in Figure 1a and the STEM-HAADF image in Figure 1b show the deposited copper nanoparticles on a silicon substrate. The elemental composition is presented by the EDX mapping. Figure 1e and Figure 1f show the silicon (yellow) and copper (blue) elemental mapping, respectively, collected

•  4d. We have extended our study by measuring the elemental line profile using STEM-HAADF-EDX, as presented in Figure 5. Two elemental line profiles for Cu, O and Si have been acquired for the as-deposited sample (Figure 5a). These profiles show a higher Cu intensity when the electron beam (along the

Photocatalysis applications of some hybrid polymeric composites incorporating TiO₂ nanoparticles and their combinations with SiO₂/Fe₂O₃

• Andreea Laura Chibac,
• Tinca Buruiana,
• Violeta Melinte and
• Emil C. Buruiana

Beilstein J. Nanotechnol. 2017, 8, 272–286, doi:10.3762/bjnano.8.30

• urethane dimethacrylate (PTHF-UDMA) to be UV photopolymerized in the presence of Irgacure 819 as photoinitiator. This process led to the formation of flexible polymer networks (S1–S4). Energy-dispersive X-ray spectroscopy (EDX) was employed to evaluate the chemical composition (qualitative and quantitative

• ) of all hybrid nanocomposites containing TiO2 NPs and also to investigate the spatial distribution of the elements through the X-ray elemental mapping images. In the EDX patterns (Figure 3), the Ti, Si and Fe signals confirmed the existence of inorganic nanoparticles, while the organic matrix is

• photopolymerization using oligomeric dimethacrylate and premade NPs. Analysis with XRD, TEM, FTIR and EDX demonstrated the formation of a nanocrystalline anatase phase of TiO2 and the uniform distribution of inorganic NPs in the polymer matrix. The hybrid films presented an appropriate photocatalytic activity under

Phosphorus-doped silicon nanorod anodes for high power lithium-ion batteries

• Chao Yan,
• Qianru Liu,
• Jianzhi Gao,
• Zhibo Yang and
• Deyan He

Beilstein J. Nanotechnol. 2017, 8, 222–228, doi:10.3762/bjnano.8.24

• changes in such a material are more homogeneous [14]. From the energy dispersive (EDX) spectra illustrated in Figure 2d (collected in the region indicated by the red box in Figure 2a), it can be concluded that phosphorus atoms exist in the Si layer with an atomic ratio of about 3%. The existence of

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• with a 14 mm diameter tubular quartz reactor was employed for the experiment. Polycrystalline copper foil (99.9% purity, proved by the EDX study) with a thickness of 60 μm was used as the catalyst. Prior to the APCVD, the foil was electrochemically polished for 5 min in 1 M phosphoric acid at a bias

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

• characteristic for Fe–O bond vibrations, the band at 555 cm−1, which may be attributed to the Cr–O lattice vibration [28]. The presence of metals in the samples was confirmed by SEM-EDX spectroscopy. In the spectra of the samples NPT2 and NPT4, the iron was detected, while in NPT3 (Supporting Information File 1

• supports the idea that sample NPC3 is an iron oxide–silica hybrid. The EDX spectrum (Supporting Information File 1, Figure S19) indeed confirms the presence of both Si and Fe in a 2.1:1 atomic ratio in the sample NPC3. In the EDX spectrum of sample NPC1, only iron was detected, while in NPC2 we could

• particles of irregular shape covered with a lower contrast material which might be silica. The diameter of the particles is in the range of 10–50 nm and the average size is 29 nm. EDX analysis (along the direction indicated in the TEM (Figure 9b)) made on aggregated nanoparticles showed both Fe and Si

Nanostructured SnO₂–ZnO composite gas sensors for selective detection of carbon monoxide

• Paul Chesler,
• Cristian Hornoiu,
• Susana Mihaiu,
• Cristina Vladut,
• Jose Maria Calderon Moreno,
• Mihai Anastasescu,
• Carmen Moldovan,
• Bogdan Firtat,
• Costin Brasoveanu,
• George Muscalu,
• Ion Stan and
• Mariuca Gartner

Beilstein J. Nanotechnol. 2016, 7, 2045–2056, doi:10.3762/bjnano.7.195

• (AFM). The microstructure of the samples was investigated by SEM using a high-resolution microscope (FEI, Quanta 3D FEG), equipped with an energy dispersive X-ray (EDX) spectrometer (Apollo X). The analyses were performed in high vacuum mode at different accelerating voltages (5–20 kV) and the sensors

A novel electrochemical nanobiosensor for the ultrasensitive and specific detection of femtomolar-level gastric cancer biomarker miRNA-106a

• Maryam Daneshpour,
• Kobra Omidfar and
• Hossein Ghanbarian

Beilstein J. Nanotechnol. 2016, 7, 2023–2036, doi:10.3762/bjnano.7.193

• spectrum of Fe3O4 and TMC@Fe3O4 NPs. Furthermore, the chemical composition of the particles was studied via EDX analysis. The EDX spectrum (Figure 2C) verified the presence of Fe, O, and Au. The considerable amounts of H, C, and N in the nanocomplex represent the TMC polymer and indicate the successful

• , Freescale) analysis. In order to study structural and elemental properties, X-ray diffraction (XRD) (Philips, pw 1800, Netherlands) and energy-dispersive X-ray diffraction (EDX) were carried out. These NPs were also characterized using Fourier transform infrared spectroscopy (FTIR) to study the chemical

Organoclay hybrid materials as precursors of porous ZnO/silica-clay heterostructures for photocatalytic applications

• Marwa Akkari,
• Pilar Aranda,
• Abdessalem Ben Haj Amara and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2016, 7, 1971–1982, doi:10.3762/bjnano.7.188

• may remain assembled to ZnO particles, perhaps organized even as core–shell structures (Figure 4C). EDX analysis of ZnO/silica-clay heterostructures shows the presence of Zn in a significant amount with respect to the Si content in all the samples. However, it is complicated to estimate the precise

• using a JEOL 2100F STEM microscopy, operating at 200 kV equipped with an EDX (INCA x-sight of Oxford Instruments) detector for semiquantitative analysis. The specimens for TEM were prepared by putting the as-grown products in ethanol and immersing them in an ultrasonic bath for 15 min, then dropping a

Cubic chemically ordered FeRh and FeCo nanomagnets prepared by mass-selected low-energy cluster-beam deposition: a comparative study

• Veronique Dupuis,
• Anthony Robert,
• Arnaud Hillion,
• Ghassan Khadra,
• Nils Blanc,
• Damien Le Roy,
• Florent Tournus,
• Clement Albin,
• Olivier Boisron and
• Alexandre Tamion

Beilstein J. Nanotechnol. 2016, 7, 1850–1860, doi:10.3762/bjnano.7.177

• carbon-coated grid and then capped it with a thin carbon film. We obtained nanoparticles with selected diameters from 2 to 5 nm, a Gaussian size distribution and a relative dispersion of around 0.15 (Figure 3). In addition, several nanoparticles were analyzed using EDX (energy dispersive X-ray analysis

• ) as shown in Figure 3c. In all cases, the EDX analysis showed no sign of oxidation of the nanoparticles and a roughly equiatomic composition for both FeRh and FeCo cluster samples conserved after 2 h annealing at 500 °C under ultra-high vacuum (UHV) conditions [10][11]. High-resolution TEM (HRTEM

• observations (b) and corresponding EDX analysis (c) of annealed mass-selected FeRh nanoparticles with an average diameter of 4.5 nm. HRTEM images for annealed FeRh nanoparticles with 2 nm in diameter (d). HRTEM images for as-prepared (a) and annealed (b) FeRh nanoparticles with their respective FFT

Thickness-modulated tungsten–carbon superconducting nanostructures grown by focused ion beam induced deposition for vortex pinning up to high magnetic fields

• Ismael García Serrano,
• Javier Sesé,
• Isabel Guillamón,
• Hermann Suderow,
• Sebastián Vieira,
• Manuel Ricardo Ibarra and
• José María De Teresa

Beilstein J. Nanotechnol. 2016, 7, 1698–1708, doi:10.3762/bjnano.7.162

• by means of energy dispersive X-ray (EDX) spectroscopy has been performed in the thicker and thinner parts of the deposits. A 3% higher Ga content and 8% lower W content is observed in the thicker parts of the deposits compared to the thinner parts. Such differences give rise to the periodic STEM

• the sample with pitch 100 nm. (a) STEM-HAADF image of the sample, including a red arrow signaling the full linear beam scan performed for the compositional analysis shown in (c). (b) Compositional data obtained from EDX spectroscopy measurements performed at the red cross and red square shown in (a

• experiment is carried out. (d) Modulation in the W composition along the red arrow line extracted from the EDX intensity at energy 1774 eV, which corresponds to the W M-edge peak. (a) Magnetoresistance curves of the sample with 100 nm pitch at 1.9 K (0.43Tc), 2.2 K (0.49Tc), 2.5 K (0.56Tc), 3 K (0.67Tc), 3.5

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• and (c, d) ZnO NR. SEM images (a, b) CdS–ZnO binary nanocomposite and (c, d) CdS–ZnO–RGO ternary nanocomposite. TEM Images (a) GO sheets, (b) CdS NP, (c) CdS–ZnO binary composite, (d) CdS–ZnO–RGO ternary composite and EDX spectrum (e) CdS–ZnO and (f) CdS–ZnO–RGO nanocomposites, respectively. FTIR

Sb₂S₃ grown by ultrasonic spray pyrolysis and its application in a hybrid solar cell

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Arvo Mere,
• Valdek Mikli and
• Malle Krunks

Beilstein J. Nanotechnol. 2016, 7, 1662–1673, doi:10.3762/bjnano.7.158

• pyramidal crystals were present in the layer (Supporting Information File 1, Figure S1b) that according to EDX were composed of antimony and oxygen only. Such Sb2O3 crystals have also been reported to be present after annealing the CBD-grown antimony sulfide films at 300 °C [44]. Indeed, the lowering of the

• at 320 °C for 30 min in N2 atmosphere showed the presence of crystalline Sb2O3 in addition to crystalline Sb2S3 when evaluated by micro-Raman spectroscopy (not shown), indicating the presence of a non-crystalline oxygen-containing phase prior to annealing in N2. EDX results support this proposition

• consist of flake-like particles, and coalesced flakes, with gaps in between that leave the TiO2 substrate partly exposed (Figure 2). The flakes are composed of S and Sb with a ratio of 1.53 measured by EDX that within measurement uncertainty corresponds to stoichiometric Sb2S3. The number density of Sb2S3

Influence of hydrothermal synthesis parameters on the properties of hydroxyapatite nanoparticles

• Sylwia Kuśnieruk,
• Jacek Wojnarowicz,
• Agnieszka Chodara,
• Tadeusz Chudoba,
• Stanislaw Gierlotka and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 1586–1601, doi:10.3762/bjnano.7.153

• ). Additionally, the XRD results of a cod bone, a human tooth with enamel and a tooth root were summarized. Pastilles with a diameter of 12 mm, obtained by pressing pulverized bones under a pressure of 10 MPa, were used for the EDX measurement. The above mentioned natural samples were used as a comparison and

Effect of tetramethylammonium hydroxide/isopropyl alcohol wet etching on geometry and surface roughness of silicon nanowires fabricated by AFM lithography

• Siti Noorhaniah Yusoh and
• Khatijah Aisha Yaacob

Beilstein J. Nanotechnol. 2016, 7, 1461–1470, doi:10.3762/bjnano.7.138

• constant concentration of IPA. This small difference occurs due to the small difference of only 10 s between the etching times. However, it is expected that the etching rate and roughness would continue to change for a longer duration of the etching time. FESEM and EDX analysis of fabricated silicon

• nanowires All of the samples underwent FESEM and EDX measurements in order to verify the formation of the silicon nanowires after the etching process. Figure 14 shows Si and O elemental analysis for all cases. The samples etched without IPA and with IPA of 10, 20 and 30 vol % contained 73.7, 73.23, 72.21

• out using FESEM and EDX. Pattern of silicon oxide nanowire with left and right square pads prior to etching. AFM images of silicon nanowire after wet etching using (a) 25 wt % TMAH (b) 25 wt % TMAH with 10 vol % IPA (c) 25 wt % TMAH with 20 vol % IPA (d) 25 wt% TMAH with 30 vol % IPA at 65 °C for 30 s

A composite structure based on reduced graphene oxide and metal oxide nanomaterials for chemical sensors

• Vardan Galstyan,
• Elisabetta Comini,
• Iskandar Kholmanov,
• Andrea Ponzoni,
• Veronica Sberveglieri,
• Nicola Poli,
• Guido Faglia and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2016, 7, 1421–1427, doi:10.3762/bjnano.7.133

• and annealed the prepared hybrid material in a furnace at 250 °C in an atmosphere of 20% O2 and 80% Ar for 1 h. The surface morphology of the samples was studied by means of a LEO 1525 scanning electron microscope (SEM) equipped with a field emission gun. Energy dispersive X-ray spectroscopy (EDX) was

• ZnO nanoparticles. Figure 3 reports the EDX spectrum and the quantitative analysis of the prepared structure. The morphological and the compositional studies confirm that the surface of ZnO nanomaterial is partially covered by GO. The variation of the C/O ratio in the GO platelets was checked by EDX

• before and after the thermal treatment at 250 °C. The EDX observations indicate that the C/O ratio increased due to the treatment, which means that GO was partially reduced (Table 1). The obtained results are in agreement with the our previous work on a similar material for the detection of explosive and

Viability and proliferation of endothelial cells upon exposure to GaN nanoparticles

• Tudor Braniste,
• Ion Tiginyanu,
• Tibor Horvath,
• Simion Raevschi,
• Serghei Cebotari,
• Marco Lux,
• Axel Haverich and
• Andres Hilfiker

Beilstein J. Nanotechnol. 2016, 7, 1330–1337, doi:10.3762/bjnano.7.124

• Figure 1. According to energy dispersive X-ray (EDX) measurements, approximately 2% of ZnO remained on the GaN nanoparticles after thermal treatment in hydrogen flow (Supporting Information File 1, Figure S1). The further removal of ZnO was not possible despite higher temperatures and longer incubation

On the pathway of cellular uptake: new insight into the interaction between the cell membrane and very small nanoparticles

• Claudia Messerschmidt,
• Daniel Hofmann,
• Anja Kroeger,
• Katharina Landfester,
• Volker Mailänder and
• Ingo Lieberwirth

Beilstein J. Nanotechnol. 2016, 7, 1296–1311, doi:10.3762/bjnano.7.121

• overall appearance of the cell – the more advanced the necrotic cellular breakdown the more distinct the dark material inside the mitochondria. These agglomerates might be due to deposition of Ca2+ salts within the mitochondria. EELS and EDX measurements revealed a significantly raised content of calcium

• tridiem image filter (Gatan Inc., USA) and an energy dispersive X-ray fluorescence (EDX) detector (EDAX Inc., USA) for analytical element measurements. Conventional bright field images were acquired using a Gatan US1000 slow scan CCD camera (Gatan Inc., USA). Inelastic dark field imaging for NP

• to the TEM brightfield image. Membrane segmentation was done in a similar way, using principal components analysis of spectrum image series [50] prior to segmentation. EELS/EDX For spatially resolved elemental analysis we applied EDX spectroscopy and electron energy loss spectroscopy (EELS). For EDX

Fabrication and characterization of branched carbon nanostructures

• Sharali Malik,
• Yoshihiro Nemoto,
• Hongxuan Guo,
• Katsuhiko Ariga and
• Jonathan P. Hill

Beilstein J. Nanotechnol. 2016, 7, 1260–1266, doi:10.3762/bjnano.7.116

• that the material has not been damaged by the fabrication procedure. The EDX analysis of the MWCNTs starting material is 100% carbon (the data sheet indicates a carbon purity of over 95%). The EDX analysis of the branched-MWNTs is 96% carbon and 4% oxygen. This is consistent with the initial heating in

• (Renishaw inVia), TEM (Tecnai F20 ST at 200 kV), HRTEM (Jeol ARM at 120 kV), SEM (Zeiss Ultra-Plus at 5 kV), SEM (Zeiss Leo 1530 at 10 kV with Oxford X-Max 50 EDX ) and helium ion microscopy (HeIM, Zeiss Orion at 30 kV). a) SEM overview of a Baytubes agglomerated pellet; b, c) SEM details of the MWCNTs; d

Mesoporous hollow carbon spheres for lithium–sulfur batteries: distribution of sulfur and electrochemical performance

• Anika C. Juhl,
• Artur Schneider,
• Boris Ufer,
• Torsten Brezesinski,
• Jürgen Janek and
• Michael Fröba

Beilstein J. Nanotechnol. 2016, 7, 1229–1240, doi:10.3762/bjnano.7.114

• spheres. It remains unclear at present, whether the cavity and the micro- or mesopores of the shell are both accessible for sulfur infiltration. The analysis of sulfur distribution in the literature is usually conducted by energy dispersive X-ray spectroscopy (EDX) measurements using either a transmission

• lack of Raman bands might also be due to confinement effects. Thus, the appearance of bands at high sulfur loadings could also be explained either by sulfur filling the cavities of HCS or by sulfur accumulating on the outside of the spheres. SEM and EDX SEM images of HCS-58-vac and HCS-67-vac (Figure

• % sulfur only show carbon spheres regardless of the impregnation method. SEM images of the composites containing 67 wt % sulfur or more indicate the presence of a second phase. This phase is darker than the spheres and is extended over large areas. Exemplary, EDX measurements of the hollow spheres and the

Manufacturing and investigation of physical properties of polyacrylonitrile nanofibre composites with SiO₂, TiO₂ and Bi₂O₃ nanoparticles

• Tomasz Tański,
• Wiktor Matysiak and
• Barbara Hajduk

Beilstein J. Nanotechnol. 2016, 7, 1141–1155, doi:10.3762/bjnano.7.106

• dedicated database of PAN-ICSD files was used. The resulting polymer composite nanofibres were quantitatively and qualitatively analysed using EDX microanalysis and surface topography imaging using a Zeiss Supra 35 SEM, with a Trident XM4 X-ray spectrometer supplied by EDAX. Based on the SEM micrographs

• (50000× magnification), the diameters of the randomly selected nanofibres were measured using the DigitalMicrograph software, and then their mean value and the chemical composition based on EDX spectra were specified. In order to study the optical properties of the obtained fibrous polymer and composite

• morphology studies of composite PAN/Bi2O3 nanofibres and the EDX analysis showed no defects in the form of agglomerates of the strengthening phase. However, with an increase of the concentration of Bi2O3 nanoparticles in the polymer to 12 wt %, the formation of spindled beads can be seen (Figure 6), which

Fast diffusion of silver in TiO₂ nanotube arrays

• Wanggang Zhang,
• Yiming Liu,
• Diaoyu Zhou,
• Hui Wang,
• Wei Liang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2016, 7, 1129–1140, doi:10.3762/bjnano.7.105

• relatively clean and smooth. Figure S3 in Supporting Information File 1 shows the line scan of EDX of the cross section of the corresponding TiO2 nanotube arrays with Ag nanofilm, which supports the SEM image shown in Figure 5c. Further increase of the temperature to 500 °C for the heat treatment introduced

Selective photocatalytic reduction of CO₂ to methanol in CuO-loaded NaTaO₃ nanocubes in isopropanol

• Tianyu Xiang,
• Feng Xin,
• Jingshuai Chen,
• Yuwen Wang,
• Xiaohong Yin and
• Xiao Shao

Beilstein J. Nanotechnol. 2016, 7, 776–783, doi:10.3762/bjnano.7.69

• electron microscope (SEM) with an accelerating voltage of 3.0 kV. The surface composition of the catalysts was investigated using a Thermo Scientific energy dispersion X-ray (EDX) fluorescence analyzer (with a Mg Kα ADES (hν = 1253.6 eV) source) as an addition to the SEM and XPS (PHA-5400, SPECS, America

Facile synthesis of water-soluble carbon nano-onions under alkaline conditions

• Gaber Hashem Gaber Ahmed,
• Rosana Badía Laíño,
• Josefa Angela García Calzón and
• Marta Elena Díaz García

Beilstein J. Nanotechnol. 2016, 7, 758–766, doi:10.3762/bjnano.7.67

• spacings were determined to be about 0.3 nm by EDX (area highlighted in Figure 3b). This spacing is slightly smaller than the interlayer spacing of (002) planes of graphite [22]. It is worth to mention that along with the C-onions some buckled structures can be observed. Assuming that C-onions grow from

Fabrication and properties of luminescence polymer composites with erbium/ytterbium oxides and gold nanoparticles

• Julia A. Burunkova,
• Ihor Yu. Denisiuk,
• Dmitri I. Zhuk,
• Lajos Daroczi,
• Attila Csik,
• István Csarnovics and
• Sándor Kokenyesi

Beilstein J. Nanotechnol. 2016, 7, 630–636, doi:10.3762/bjnano.7.55

• the direct absorption of erbium ions at 980 nm has a low efficiency, but for ytterbium ions it is highly efficient and the ytterbium ions can transfer excitation energy to the erbium ions. Energy dispersive X-ray analysis (EDX) in a scanning electron microscope (SEM) was used for determining the

• . EDX spectra of the synthesized Er/Yb oxide particles with SiO2 NPs. XRD spectrum of the Er/Yb oxides embedded into silicon oxide powder. Spectra of luminescence excited at 488 nm. a) Initial powder mixture of Er/Yb chlorides (1), Er/Yb oxides powder, obtained with SiO2 NPs (2); b) oxide particles in