The microstrain-accompanied structural phase transition from h-MoO₃ to α-MoO₃ investigated by in situ X-ray diffraction

• Zeqian Zhang,
• Honglong Shi,
• Boxiang Zhuang,
• Minting Luo and
• Zhenfei Hu

Beilstein J. Nanotechnol. 2023, 14, 692–700, doi:10.3762/bjnano.14.55

• der Waals coupling between layers [20]. β-MoO3 is a metastable phase in which the MoO6 octahedra share corners in three dimensions to construct a monoclinic structure [16]. h-MoO3 is a metastable hexagonal phase. It has the unique structural characteristic that the MoO6 octahedra chains share corners

• raised to 380 °C, some weak diffraction peaks at 12.56°, 23.29°, 25.25°, and 27.29° appeared, indicating the beginning formation of a new phase. At 450 °C, the hexagonal phase disappeared entirely, and the XRD pattern became that of the orthorhombic phase (PDF#35-0609). For the orthorhombic phase, α-MoO3

• boundary may improve the photocatalytic performance of MoO3. The crystal structures of h-MoO3 and α-MoO3 The crystal structure of the hexagonal phase h-MoO3 Thermogravimetric results [23][24][25] indicate that the h-MoO3 phase releases water molecules during heat treatment, suggesting that water molecules

Gas-sensing features of nanostructured tellurium thin films

• Dumitru Tsiulyanu

Beilstein J. Nanotechnol. 2020, 11, 1010–1018, doi:10.3762/bjnano.11.85

• to Figure 2A, the XRD pattern of films grown on Pyrex glass substrates reveals a highly crystalline structure with a predominant Te hexagonal phase. The positions of the most intense peaks matched the reference values: from right to left, the first peak occurs due to the reflection from the (100

Internalization mechanisms of cell-penetrating peptides

• Ivana Ruseska and
• Andreas Zimmer

Beilstein J. Nanotechnol. 2020, 11, 101–123, doi:10.3762/bjnano.11.10

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• a predominantly hexagonal crystal structure. Minor peaks at 47° (220) and 55° (311) 2θ indicate a small fraction of the cubic phase. The XRD patterns of the silica-coated UCNPs show the same peaks (mainly the hexagonal phase) with decreasing intensity as the silica shell thickness increases

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)₃:Eu³⁺ nanoparticles for white light generation

• Tugrul Guner,
• Anilcan Kus,
• Mehmet Ozcan,
• Aziz Genc,
• Hasan Sahin and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 1200–1210, doi:10.3762/bjnano.10.119

• ., unreacted yttrium acetate) is given for the comparison. The reflections can be indexed to hexagonal phase (space group of P63/m) Y(OH)3 with lattice constants of a = 6.261 Å, b = 6.261 Å, and c = 3.544 Å corresponding to JCPDS: 01-083-2042. The evolution of the crystal is clearly seen in the stack plot of

• structure indicates two yttrium atoms located at one face of the hexagonal phase and shared oxygen saturated with hydrogens. To investigate the crystal formation of the samples fabricated at 5 min, several low-magnification high-angle annular dark field (HAADF) STEM micrographs were taken and are presented

Near-infrared light harvesting of upconverting NaYF₄:Yb³⁺/Er³⁺-based amorphous silicon solar cells investigated by an optical filter

• Daiming Liu,
• Qingkang Wang and
• Qing Wang

Beilstein J. Nanotechnol. 2018, 9, 2788–2793, doi:10.3762/bjnano.9.260

• phase transition is completed after 12 h. In Figure 1c, energy-dispersive X-ray (EDX) analysis confirms the doping with Yb and Er. The molar ratio of Y/Yb/Er in the hexagonal phase NaYF4:Yb3+/Er3+ was determined to be 79.8:18.2:2. It is extremely close to the stoichiometric ratio of 80:18:2 of the most

• as an increase in the fraction of the hexagonal phase. The quantum efficiency of the hexagonal nanorods is about an order of magnitude higher than that of the cubic phase counterparts [17]. The photoluminescence of NaYF4:Yb3+/Er3+ is explained by energy transfer between Yb3+ and Er3+. As illustrated

• nanorods (Figure 4d). The scattering effect changes the propagation direction of light and elongates the propagation path in the photoactive layer of the solar cell, thus enhancing the light harvesting of visible light. Conclusion We have used hexagonal-phase NaYF4:Yb3+/Er3+ (18/2 mol %) nanorods on the

Ag₂WO₄ nanorods decorated with AgI nanoparticles: Novel and efficient visible-light-driven photocatalysts for the degradation of water pollutants

• Shijie Li,
• Shiwei Hu,
• Wei Jiang,
• Yanping Liu,
• Yu Liu,
• Yingtang Zhou,
• Liuye Mo and
• Jianshe Liu

Beilstein J. Nanotechnol. 2018, 9, 1308–1316, doi:10.3762/bjnano.9.123

• indexed to (002), (231), (400), (402), (361) and (333) diffraction planes, respectively [31][41]. The diffraction peaks of pure AgI match well with those of the standard hexagonal phase (JCPS no 29-1154) [43]. It can be seen that all the AgI/Ag2WO4 composites display both Ag2WO4 and AgI phases. Of note is

Liquid-crystalline nanoarchitectures for tissue engineering

• Baeckkyoung Sung and
• Min-Ho Kim

Beilstein J. Nanotechnol. 2018, 9, 205–215, doi:10.3762/bjnano.9.22

• columnar hexagonal phase (380–670 mg/mL) to the crystalline phase. The isotropic phase is the solution at a low rod concentration and lacks orientational and positional orders. In the nematic phase, orientational order is introduced by volume exclusion effects, in a way that the rods are aligned more or

• within each layer. In smectic-B, this liquid-like order is replaced by a hexagonal positional order. The smectic-B phase has not been observed in DNA systems. In the columnar hexagonal phase, the rods are unidirectionally aligned by maintaining a local hexagonal order. The lamellar order is no longer

• preferred in this phase. The columnar phase is fundamentally different from the crystalline phase in the sense that the rod suspensions exhibit fluidity and viscoelasticity. The crystalline phase is a complete solid state where the rods are fully ordered and tightly bound to each other in a 3D hexagonal

Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• . Hexagonal phase sodium gadolinium fluoride β-NaGdF4 is an ideal matrix for the creation optical/magnetic dual-modal bioprobes, but upconversion luminescence (UCL) efficiency of this host material is still low and needs to be improved. A major method to enhance the UCL intensity is to use a core–shell

• demonstrate the effective surface modification method that uses a surfactant polysorbate 80 (Tween 80, polyoxyethylene sorbitan laurate). Hexagonal phase β-NaGdF4 was chosen as host lattice for its ability to combine optical and MRI. Tween 80 was used to make the UCNPs colloidally stable and dispersible in

• lanthanide dopants from being quenched, and also negate the influence of surface defects. The results correlate well with what is presented in the literature. Yi et al. reported that the UC emissions of hexagonal phase NaYF4:Yb3+,Er3+ were enhanced by as much as seven times by growth of a 2 nm layer of NaYF4

AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• measurements confirmed the presence of cubic-phase undoped nanoparticles. Also, there is an increase in the amount of the hexagonal phase in NPs when the AgCl concentration is increased during synthesis. Hexagonal-phase NPs were obtained at the highest AgCl concentrations (Ag to Cd ratios above 1:1 during

• synthesis). The particle morphology was also controlled by the amount of AgCl during synthesis. The addition of AgCl allowed us to obtain tetrapods and large ellipsoidal NPs. Tetrapods have a cubic-phase core and hexagonal-phase legs. Large ellipsoidal NPs are mostly diphasic. In our work we assume that

ZnO nanoparticles sensitized by CuInZn_xS_2+x quantum dots as highly efficient solar light driven photocatalysts

• Florian Donat,
• Serge Corbel,
• Halima Alem,
• Steve Pontvianne,
• Lavinia Balan,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 1080–1093, doi:10.3762/bjnano.8.110

• nm) after the thermal treatment at 400 °C (Figure 1d). No aggregation of ZCIS particles was observed from the TEM image after this annealing process. The HR-TEM image and the interplanar spacings measured confirm the co-existence of ZnO in the hexagonal phase and ZCIS particles with a tetragonal

Effect of nanostructured carbon coatings on the electrochemical performance of Li_1.4Ni_0.5Mn_0.5O_2+x-based cathode materials

• Konstantin A. Kurilenko,
• Oleg A. Shlyakhtin,
• Oleg A. Brylev,
• Dmitry I. Petukhov and
• Alexey V. Garshev

Beilstein J. Nanotechnol. 2016, 7, 1960–1970, doi:10.3762/bjnano.7.187

• during cycling, the contact of Li1.4Ni0.5Mn0.5O2+x with electrolyte results in an interaction leading to the formation of a Li-deficient spinel Lix(Ni0.5Mn0.5)2O4, and, later, cubic (Ni0.5Mn0.5)O [37]. Other authors observed a slow transformation of the hexagonal phase into a cubic phase in the course of

Microwave solvothermal synthesis and characterization of manganese-doped ZnO nanoparticles

• Jacek Wojnarowicz,
• Roman Mukhovskyi,
• Elzbieta Pietrzykowska,
• Sylwia Kusnieruk,
• Jan Mizeracki and
• Witold Lojkowski

Beilstein J. Nanotechnol. 2016, 7, 721–732, doi:10.3762/bjnano.7.64

• agglomeration and formation of conglomerates of Zn1−xMnxO NPs. Phase composition The XRD tests of the samples did not reveal a presence of foreign phases in the obtained Zn1−xMnxO NPs, and all diffraction peaks can be attributed to the hexagonal phase ZnO (Figure 5). Zinc oxide is characterised by hexagonal

Sonochemical co-deposition of antibacterial nanoparticles and dyes on textiles

• Ilana Perelshtein,
• Anat Lipovsky,
• Nina Perkas,
• Tzanko Tzanov and
• Aharon Gedanken

Beilstein J. Nanotechnol. 2016, 7, 1–8, doi:10.3762/bjnano.7.1

• textile surface where they remain strongly embedded. Indeed, the XRD patterns of the fabric at the end of the reaction revealed the formation of MO NPs on the surface (Figure 1). The XRD pattern of the sonochemically prepared ZnO NPs correspond to hexagonal phase of zincite (Figure 1a). The peaks at 2θ

Silica-coated upconversion lanthanide nanoparticles: The effect of crystal design on morphology, structure and optical properties

• Uliana Kostiv,
• Miroslav Šlouf,
• Hana Macková,
• Alexander Zhigunov,
• Hana Engstová,
• Katarína Smolková,
• Petr Ježek and
• Daniel Horák

Beilstein J. Nanotechnol. 2015, 6, 2290–2299, doi:10.3762/bjnano.6.235

• diffraction (XRD) to determine morphology, size, polydispersity, crystal structure and elemental composition of the nanocrystals. TEM microscopy revealed that the morphology of the nanoparticles could be fine-tuned by modifying of the synthetic conditions. A cubic-to-hexagonal phase transition of the NaYF4

• hexagonal OM–NaYF4:Yb3+/Er3+ phase increased significantly. The particles obtained at 330 and 350 °C exhibited the hexagonal phase, but traces of the cubic phase were still present in the lower temperature particles. The position of the XRD peaks (Figure 3a) corresponded to the hexagonal phase, as published

• of an amorphous halo is indicative of a disorder-to-order type cubic-to-hexagonal phase transition [39]. The size of α crystallites ranged from 6 to 6.5 nm, and the size of β-phase crystals ranged between 18–21 nm. Interestingly, diffraction peaks corresponding to the cubic phase were hardly visible

Fringe structures and tunable bandgap width of 2D boron nitride nanosheets

• Peter Feng,
• Muhammad Sajjad,
• Eric Yiming Li,
• Hongxin Zhang,
• Jin Chu,
• Ali Aldalbahi and
• Gerardo Morell

Beilstein J. Nanotechnol. 2014, 5, 1186–1192, doi:10.3762/bjnano.5.130

• ). The microscope focused the laser beam onto the surface of the sample. Comparison of two spectral lines before and after treatment, two phenomena can be identified: 1) typical Raman active E2g mode of BNNSs with the hexagonal phase shifts from 1365 cm−1 to 1354 cm−1. This suggests that the bandgap

Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Vandana Choudhary,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2014, 5, 639–650, doi:10.3762/bjnano.5.75

• because of the presence of many small crystals and suggests the crystalline nature of heterostructures. The SAD pattern further confirms the formation of crystalline hexagonal phase of Ag–ZnO hybrid nanostructures. The high-resolution TEM image of ZnO nanostructures in Figure 3b clearly shows lattice

High activity of Ag-doped Cd_0.1Zn_0.9S photocatalyst prepared by the hydrothermal method for hydrogen production under visible-light irradiation

• Leny Yuliati,
• Melody Kimi and
• Mustaffa Shamsuddin

Beilstein J. Nanotechnol. 2014, 5, 587–595, doi:10.3762/bjnano.5.69

• (111), (200), (220) and (311) planes respectively. On the other hand, in addition to the cubic zinc blende phase, the Ag(0.05)-doped Cd0.1Zn0.9S also showed the presence of small diffraction peaks of the hexagonal phase at 2θ of ca. 27 and 31° (Figure 1d). A similar phenomenon was also reported when Cu

Preparation of poly(N-vinylpyrrolidone)-stabilized ZnO colloid nanoparticles

• Tatyana Gutul,
• Emil Rusu,
• Nadejda Condur,
• Veaceslav Ursaki,
• Evgenii Goncearenco and
• Paulina Vlazan

Beilstein J. Nanotechnol. 2014, 5, 402–406, doi:10.3762/bjnano.5.47

• °, 56.84°, 63.12°, 66.52°, 68.12°, 69.18°, 72.58°, and 77.08° are observed, which correspond to the hexagonal phase of ZnO nanoparticles (space group P63mc, a = 3.249 Å, c = 5.206 Å). The size d of ZnO particles was estimated from the width of the most intense peak according to the Scherrer formula d = k·λ

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• . All the diffraction peaks can be attributed to two well-defined phases, which are hexagonal-phase graphitic carbon {26.4° (002); JCPDS-041-1487} and cubic-phase Fe3O4 {JCPDS-019-0629}. No signals for metallic iron or other oxides were detected in the XRD pattern, which indicates that the oxidation

Focused electron beam induced deposition: A perspective

• Michael Huth,
• Fabrizio Porrati,
• Christian Schwalb,
• Marcel Winhold,
• Roland Sachser,
• Maja Dukic,
• Jonathan Adams and
• Georg Fantner

Beilstein J. Nanotechnol. 2012, 3, 597–619, doi:10.3762/bjnano.3.70

• × 1015 cm−2) [31]. The annealing was done at 400 °C for different time periods. The crystal structure of this metastable phase was resolved to be hexagonal, belonging to the space group P6/mmc [31]. Annealing at elevated temperatures (550 °C and above) leads to the destruction of the hexagonal phase

Investigation on structural, thermal, optical and sensing properties of meta-stable hexagonal MoO₃ nanocrystals of one dimensional structure

• Angamuthuraj Chithambararaj and
• Arumugam Chandra Bose

Beilstein J. Nanotechnol. 2011, 2, 585–592, doi:10.3762/bjnano.2.62

• characteristic peaks of molybdenum and oxygen. Thermogravimetric (TG) analysis on metastable MoO3 revealed that the hexagonal phase was stable up to 430 °C and above this temperature complete transformation into a highly stable orthorhombic phase was achieved. The optical band gap energy was estimated from the

• Kubelka–Munk (K–M) function and was found to be 2.99 eV. Finally, the ethanol vapor-sensing behavior was investigated and the sensing response was found to vary linearly as a function of ethanol concentration in the parts per million (ppm) range. Keywords: fiber optic sensor; hexagonal phase; molybdenum

• for the first time the ethanol vapor-sensing mechanism with h-MoO3 by fiber optics sensor. Results and Discussion Crystal phase analysis The XRD pattern of the as-synthesized MoO3 powder is shown in Figure 1. The sample product crystallizes in the hexagonal phase of MoO3, and the diffraction peaks are