Precise local control of liquid crystal pretilt on polymer layers by focused ion beam nanopatterning

• Maxim V. Gorkunov,
• Irina V. Kasyanova,
• Vladimir V. Artemov,
• Alena V. Mamonova and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2019, 10, 1691–1697, doi:10.3762/bjnano.10.164

• particular LC alignments are highly valuable. Thin polymer layers induce either vertical alignment of nematic LCs, with the director oriented orthogonally to the interface plane, or planar alignment, with the director aligned in parallel to this plane. It was empirically established half a century ago that

• layer thickness d, and the LC director distribution within the layer. For the particular LC cell with vertical alignment at one substrate and planar alignment at the other, the retardation is approximately Γ0 ≃ πΔnd/λ, i.e., two times smaller than that for a uniform birefringent planar LC layer of the

Site-specific growth of oriented ZnO nanocrystal arrays

• Rekha Bai,
• Dinesh K. Pandya,
• Sujeet Chaudhary,
• Veer Dhaka,
• Vladislav Khayrudinov,
• Jori Lemettinen,
• Christoffer Kauppinen and
• Harri Lipsanen

Beilstein J. Nanotechnol. 2019, 10, 274–280, doi:10.3762/bjnano.10.26

• electrodeposition technique. Further, vertically aligned periodic nanocrystal (NC) growth is engineered at predefined positions on polymer-coated ITO substrates patterned with ordered pores. The vertical alignment of ZnO NCs along the c-axis is achieved via ion-by-ion nucleation-controlled growth for patterned

Pattern generation for direct-write three-dimensional nanoscale structures via focused electron beam induced deposition

• Lukas Keller and
• Michael Huth

Beilstein J. Nanotechnol. 2018, 9, 2581–2598, doi:10.3762/bjnano.9.240

• GIS to the place of deposition is much smaller than the precursor supply by diffusion from the substrate. We note that the simple shadow avoiding algorithm with a virtual vertical alignment of the GIS can guarantee that no higher DEs are written before lower ones (e.g., if one has to deal with initial

ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

• Marina Krasovska,
• Vjaceslavs Gerbreders,
• Irena Mihailova,
• Andrejs Ogurcovs,
• Eriks Sledevskis,
• Andrejs Gerbreders and
• Pavels Sarajevs

Beilstein J. Nanotechnol. 2018, 9, 2421–2431, doi:10.3762/bjnano.9.227

• with a ZnO seed layer in order to provide adhesion of the nanostructured ZnO film to the glass surface, as well as epitaxial growth and the vertical alignment of nanostructures. It was prepared by dip coating using 5 mM zinc acetate (Zn(O2CCH3)2) solution in ethanol. The seed layer film was dried in a

Block copolymers for designing nanostructured porous coatings

• Roberto Nisticò

Beilstein J. Nanotechnol. 2018, 9, 2332–2344, doi:10.3762/bjnano.9.218

• ), where 2-propanol was determined to be the best solvent. As reported in Figure 4, the nanoporous thin membrane (i.e., pore size ≈20 nm) adheres to the macroporous substrate without any discontinuities. As reported in Figure 4d, the desired vertical alignment of the nanoporous system is maintained, even

Toward the use of CVD-grown MoS₂ nanosheets as field-emission source

• Geetanjali Deokar,
• Nitul S. Rajput,
• Junjie Li,
• Francis Leonard Deepak,
• Wei Ou-Yang,
• Nicolas Reckinger,
• Carla Bittencourt,
• Jean-Francois Colomer and
• Mustapha Jouiad

Beilstein J. Nanotechnol. 2018, 9, 1686–1694, doi:10.3762/bjnano.9.160

• homogeneous distribution and vertical alignment compared to the previously reported MoS2 nanostructures (on which FE studies were performed), which were sparsely and randomly distributed [9]. The NSs reported by Kashid et al. have few protruding MoS2 NSs and mostly planar surfaces [12]. A typical Raman

Study of the vertically aligned in-plane switching liquid crystal mode in microscale periodic electric fields

• Artur R. Geivandov,
• Mikhail I. Barnik,
• Irina V. Kasyanova and
• Serguei P. Palto

Beilstein J. Nanotechnol. 2018, 9, 11–19, doi:10.3762/bjnano.9.2

• experimental measurements. Keywords: electrooptics; in-plane switching; liquid crystals; vertical alignment; Introduction In 1997, Lee and co-workers discovered a new LC switching mode and called it vertically aligned in-plane switching (VA-IPS) mode [1]. At that time researchers were looking for LC modes

Localized growth of carbon nanotubes via lithographic fabrication of metallic deposits

• Fan Tu,
• Martin Drost,
• Imre Szenti,
• Janos Kiss,
• Zoltan Kónya and
• Hubertus Marbach

Beilstein J. Nanotechnol. 2017, 8, 2592–2605, doi:10.3762/bjnano.8.260

• ], nanoscale actuators [38], and on-chip coolers [5]. A CNT forest is defined as CNTs grown with high density and vertical alignment. Therefore, it is necessary to increase the number of the CNTs grown per surface area. Corresponding attempts on the native oxide surface on Si(100) used for the results

• enlarged to 10 µm (Figure 7a). Correspondingly Figure 7b,c depicts the results of CNT growth via CVD at two different temperatures: 1073 K and 1133 K. At the lower CVD temperature of 1073 K, CNTs were obtained, apparently with high yield but not with a consistently vertical alignment. However, after growth

• as evidenced via TEM. Additionally, CNTs patterned in high density with vertical alignment, referred to as CNT forests, were produced on Fe deposits fabricated on an Al2O3 substrate. It can be stated that the Al2O3 supports the growth and enhances the yield of CNTs, given that a lower temperature was

Process-specific mechanisms of vertically oriented graphene growth in plasmas

• Subrata Ghosh,
• Shyamal R. Polaki,
• Niranjan Kumar,
• Sankarakumar Amirthapandian,
• Mohamed Kamruddin and
• Kostya (Ken) Ostrikov

Beilstein J. Nanotechnol. 2017, 8, 1658–1670, doi:10.3762/bjnano.8.166

• same sp3 content in the film. The effects of the substrate temperature and the electric field in vertical alignment of the graphene sheets are reported. These findings help to develop and optimize the process conditions to produce VGNs tailored for applications including sensing, field emission

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

• Amanda García-García,
• Ricardo Vergaz,
• José F. Algorri,
• Gianluigi Zito,
• Teresa Cacace,
• Antigone Marino,
• José M. Otón and
• Morten A. Geday

Beilstein J. Nanotechnol. 2016, 7, 825–833, doi:10.3762/bjnano.7.74

• speed up relaxation, since the CNT will switch oppositely to the LC and provide a pseudo volume stabilization of the vertical alignment negative (VAN) structure. Experimental The samples used for the impedance measurements were formed by two 0.7 mm thick ITO-coated glass plates (Glasstone) with

Integration of ZnO and CuO nanowires into a thermoelectric module

• Dario Zappa,
• Simone Dalola,
• Guido Faglia,
• Elisabetta Comini,
• Matteo Ferroni,
• Caterina Soldano,
• Vittorio Ferrari and
• Giorgio Sberveglieri

Beilstein J. Nanotechnol. 2014, 5, 927–936, doi:10.3762/bjnano.5.106

• conductance comes from the electrical conductivity along the axis of the nanowires. As-grown nanowires do not show any particular alignment respect to the substrate surface, as a result of combined growth mechanism and mechanical stress. Some degree of vertical alignment would not have improved the overall

• morphology of the nanostructures. The diameter of CuO nanowires grown at 400 °C was almost doubled compared to CuO grown at 250 °C. Moreover, the nanowires showed a higher degree of vertical alignment compared to the ones fabricated at lower oxidizing temperature. Figure 2c shows the applied temperature

Gas sensing with gold-decorated vertically aligned carbon nanotubes

• Prasantha R. Mudimela,
• Mattia Scardamaglia,
• Oriol González-León,
• Nicolas Reckinger,
• Rony Snyders,
• Eduard Llobet,
• Carla Bittencourt and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2014, 5, 910–918, doi:10.3762/bjnano.5.104

• vertical alignment was obtained. The deposition of gold particles by PVD restricts the formation particles at the sample surface (region near the tips), a slight increase in the oxygen content after the gold deposition was associated with formation of defects. The CNT length was found to play an important

En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays

• Slawomir Boncel,
• Sebastian W. Pattinson,
• Valérie Geiser,
• Milo S. P. Shaffer and
• Krzysztof K. K. Koziol

Beilstein J. Nanotechnol. 2014, 5, 219–233, doi:10.3762/bjnano.5.24

• ., for the reduction of nitrogen oxides (NxOy) emission in exhausts [15]. A high degree of vertical alignment in the nanotube films (also called ‘carpets’ or ‘forests’) is a key aspect in numerous applications that gain from anisotropy, i.e., supercapacitors [16], counter electrodes [17], structural

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• pressure, gas flow ratio, and plasma power among others) on the surface morphology and the chemical composition of VA-CNTs. As opposed to the wet chemical treatment, the plasma treatment does not destroy the vertical alignment of the nanotubes. By contrast, a significant surface morphology alteration is

The oriented and patterned growth of fluorescent metal–organic frameworks onto functionalized surfaces

• Jinliang Zhuang,
• Jasmin Friedel and
• Andreas Terfort

Beilstein J. Nanotechnol. 2012, 3, 570–578, doi:10.3762/bjnano.3.66

• , respectively. More interestingly, the nanoplate crystals show a highly vertical alignment at the MTCA surface hinting at a preferred crystallographic orientation. Out-of-plane surface X-ray diffraction (SXRD, Figure 4c) supports this assumption, since only two diffraction peaks at 2θ = 8.1 and 16.2° were