Defects and defect-mediated engineering of two-dimensional materials: challenges and open questions

• Arkady V. Krasheninnikov,
• Matthias Batzill,
• Anouar-Akacha Delenda,
• Marija Drndić,
• Chris Ewels,
• Katharina J. Franke,
• Mahdi Ghorbani-Asl,
• Alexander Holleitner,
• Ado Jorio,
• Ute Kaiser,
• Daria Kieczka,
• Hannu-Pekka Komsa,
• Jani Kotakoski,
• Manuel Längle,
• David Lamprecht,
• Yun Liu,
• Steven G. Louie,
• Janina Maultzsch,
• Thomas Michely,
• Katherine Milton,
• Anna Niggas,
• Hanako Okuno,
• Joshua A. Robinson,
• Marika Schleberger,
• Bruno Schuler,
• Alexander Shluger,
• Kazu Suenaga,
• Kristian S. Thygesen,
• Richard A. Wilhelm,
• E. Harriet Åhlgren and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2026, 17, 454–488, doi:10.3762/bjnano.17.31

• -active modes of the host material regarding peak position, lineshape, and the relative intensities of peaks. The position and relative intensities are affected by strain and doping induced by defects. In addition, relaxation of the translation symmetry leads to activation of modes that would otherwise be

• (ODMR) has overcome this limitation by exploiting spin-selective non-radiative pathways, enabling optical initialization and single-spin readout in wide-bandgap materials [149]. Yet, ODMR is not universal: It requires both optically bright transitions and spin-dependent relaxation channels, restricting

Biomimetic nanoparticles in cancer photodynamic therapy: a review of targeted delivery systems and therapeutic outcomes

• Valentina I. Gorbacheva,
• Alexey S. Grabovoy,
• Polina S. Marukhina,
• Anastasiia O. Syrocheva and
• Ekaterina P. Kolesova

Beilstein J. Nanotechnol. 2026, 17, 396–422, doi:10.3762/bjnano.17.27

• nanostructured materials, significantly expanding the range of agents available for PDT applications [18]. The photochemical pathway for ROS generation involves non-radiative relaxation of the excited PS, typically occurring through two primary mechanisms [19]. Type-I reactions involve electron transfer

• generation requires efficient excitation and minimal competing non-ROS-producing relaxation pathways. Low dark toxicity minimizes harm in the absence of light. High stability and low aggregation under physiological conditions are essential for maintaining photochemical activity [22]. A balanced

Ferroelectric nanodot reservoir for neuromorphic computing

• Anna Razumnaya,
• Yuri Tikhonov,
• Dmitrii Naidenko,
• Léo Boron,
• Valerii Vinokur and
• Igor Lukyanchuk

Beilstein J. Nanotechnol. 2026, 17, 352–364, doi:10.3762/bjnano.17.24

• the original configuration (). Likewise, the inverse sequence (−2q,+2q) results in full up-polarization, followed by relaxation into a new asymmetric state (). These examples highlight the rich state transition dynamics available in ferroelectric reservoirs due to the combination of hysteresis

• . Since the voltage response reflects complex nonlinear processes such as switching and relaxation, it serves as a rich source of output features, analogous to synaptic signals in neuromorphic circuits. A further signal integration scheme, illustrated in Figure 6c, uses spatial multiplexing, where

• -density neuromorphic circuits. The proposed ferroelectric reservoir benefits from several advantageous physical properties intrinsic to nanoscale ferroelectrics – high capacity, with exponentially growing configuration space, fading memory, provided by the slow relaxation dynamics of polarization in

Beam shaping techniques for pulsed laser ablation in liquids: Unlocking tunable control of nanoparticle synthesis in liquids

• Sergio Molina-Prados,
• Nadezhda M. Bulgakova,
• Alexander V. Bulgakov,
• Jesus Lancis,
• Gladys Mínguez Vega and
• Carlos Doñate-Buendia

Beilstein J. Nanotechnol. 2026, 17, 309–342, doi:10.3762/bjnano.17.22

• , which makes CLAL unfeasible for continuous or large-scale nanoparticle production [5]. Nanosecond pulses significantly reduce the thermal interaction with the liquid, but their pulse duration is longer than the typical material electron–phonon relaxation time, of the order of 0.1–10 ps for metals

Fast vortex dynamics and relaxation times in NbRe-based heterostructures

• Francesco De Chiara,
• Zahra Makhdoumi Kakhaki,
• Francesco Avitabile,
• Francesco Colangelo,
• Abhishek Kumar,
• Carmine Attanasio and
• Carla Cirillo

Beilstein J. Nanotechnol. 2026, 17, 292–302, doi:10.3762/bjnano.17.20

• to extract the quasiparticle energy relaxation time. For external magnetic field values for which edge barrier pinning is dominant and thermal effects are negligible, the relaxation times are about 150 ps and 24 ps for NbRe/Au and NbRe/Py bilayers, respectively. These results indicate that NbRe/Py

• bilayers, having a relaxation time one order of magnitude smaller than values reported in NbRe microbridges, have great potential for the realization of devices where fast relaxation processes are required. Keywords: flux-flow instability; quasiparticle relaxation time; superconducting heterostructures

• the onset of the instability to the maximum value of vortex velocity, v*, and the quasiparticle relaxation time, τE. The latter characterizes how efficiently quasiparticles (unpaired electrons) return to their equilibrium state from a non-equilibrium one [9]. τE represents a key parameter for the

Internal 3D temperature mapping in biological systems using ratiometric light-sheet imaging and lipid-coated upconversion nanothermometers

• Dannareli Barron-Ortiz,
• Enric Pérez-Parets,
• Rubén D. Cadena-Nava,
• Emilio J. Gualda,
• Jacob Licea-Rodríguez,
• Juan Hernández-Cordero,
• Pablo Loza-Álvarez and
• Israel Rocha-Mendoza

Beilstein J. Nanotechnol. 2025, 16, 2306–2316, doi:10.3762/bjnano.16.159

• cross-relaxation, can also affect temperature sensing [37][54]. These effects may introduce variations in the FIR calibration, requiring careful evaluation for accurate thermometry [35][55]. This concern is particularly relevant in Er3+-based FIR thermometry as its sensitivity strongly depends on the

Improving magnetic properties of Mn- and Zn-doped core–shell iron oxide nanoparticles by tuning their size

• Dounia Louaguef,
• Ghouti Medjahdi,
• Sébastien Diliberto,
• Klaus M. Seemann,
• Thomas Gries,
• Joelle Bizeau,
• Damien Mertz,
• Eric Gaffet and
• Halima Alem

Beilstein J. Nanotechnol. 2025, 16, 2285–2295, doi:10.3762/bjnano.16.157

• generate heat through Brownian and Néel relaxation mechanisms [4]. The heat generation capacity of these nanoparticles is often quantified by the specific absorption rate (SAR), which represents the power dissipated as heat per gram of nanoparticles under the influence of an alternating magnetic field. The

• to note, however, that magnetic anisotropy alone does not guarantee enhanced heating efficiency. As highlighted by Dirba et al., there exists an optimal range of magnetic anisotropy for effective energy dissipation in alternating magnetic fields [22]. Excessively high anisotropy may hinder relaxation

• processes and reduce SAR values. In our system, the MnFe2O4 shell likely provides anisotropy within an effective range, enabling efficient Néel and Brownian relaxation while maintaining superparamagnetic behavior [23]. Thus, the observed SAR values result from a balanced interplay between particle size

Chiral plasmonic nanostructures fabricated with circularly polarized light

• Tian Qiao and
• Ming Lee Tang

Beilstein J. Nanotechnol. 2025, 16, 2245–2264, doi:10.3762/bjnano.16.154

Calibration of piezo actuators and systems by dynamic interferometry

• Knarik Khachatryan and
• Michael Reichling

Beilstein J. Nanotechnol. 2025, 16, 2086–2091, doi:10.3762/bjnano.16.143

• interferometer is forced back to the initial condition of perfect alignment before each run of amplitude calibration. To allow for piezo relaxation after significant extension or retraction, a waiting time of 10 min has been applied between the change in and the following calibration measurement. The amplitude

Molecular and mechanical insights into gecko seta adhesion: multiscale simulations combining molecular dynamics and the finite element method

• Yash Jain,
• Saeed Norouzi,
• Tobias Materzok,
• Stanislav N. Gorb and
• Florian Müller-Plathe

Beilstein J. Nanotechnol. 2025, 16, 2055–2076, doi:10.3762/bjnano.16.141

• iterations (1.4 ns) was conducted without any applied displacement. Unlike in typical AFM experiments, where the seta is pulled sideways (sheared) to increase the contact area, we did not actively shear. However, spontaneous sliding of the spatulae was observed during preloading. (4) After relaxation, during

• . In Figure 8, the relaxation phase is the single data point at 225.4 ns (load step 161) consisting of ten FEM–MD iterations (1.4 ns), and the transition to pull-off is identified by a reversal in the force direction from positive (compression) to negative (adhesion). As the pull-off continued, we

Stereodiscrimination of guests in chiral organosilica aerogels studied by ESR spectroscopy

• Sebastian Polarz,
• Yasar Krysiak,
• Martin Wessig and
• Florian Kuhlmann

Beilstein J. Nanotechnol. 2025, 16, 2034–2054, doi:10.3762/bjnano.16.140

• , one is able to gather information about transport processes happening at 1–3 nm. If one selects an appropriate spin probe, the ESR spectra contain much valuable information. Line shape analysis and spin relaxation times can provide information on the motion and reactivity of trapped radicals. This can

Laser ablation in liquids for shape-tailored synthesis of nanomaterials: status and challenges

• Natalie Tarasenka

Beilstein J. Nanotechnol. 2025, 16, 1963–1997, doi:10.3762/bjnano.16.137

• properties of the surrounding liquid and NPs, and kinetics of relaxation processes in the surrounding medium), thus providing a playground for tailoring NP properties. In general, laser pulses of moderate fluences and longer durations are preferable for shape modification, providing mild conditions and

• by estimation of the absorbed and dissipated heat fluxes from the laser heated NPs. Apart from the laser parameters, these fluxes are determined by NP size and composition as well as by properties of the surrounding liquid which define the kinetics of relaxation processes. The balance between

• into account. [73]. The presence of the gaseous bubble around the heated particles influences the kinetics of the relaxation processes as well as the absorption of the laser beam by the NPs. In [67], the conditions required for melting silver and copper NPs with the formation of a metastable AgCu alloy

Quantum circuits with SINIS structures

• Mikhail Tarasov,
• Mikhail Fominskii,
• Aleksandra Gunbina,
• Artem Krasilnikov,
• Maria Mansfeld,
• Dmitrii Kukushkin,
• Andrei Maruhno,
• Valeria Ievleva,
• Mikhail Strelkov,
• Daniil Zhogov,
• Konstantin Arutyunov,
• Vyacheslav Vdovin,
• Vladislav Stolyarov and
• Valerian Edelman

Beilstein J. Nanotechnol. 2025, 16, 1931–1941, doi:10.3762/bjnano.16.134

• problems in explaining results is that, when the injection rate of electrons exceeds the internal relaxation rate in the metal to be cooled, the electrons do not obey the Fermi–Dirac distribution, and the concept of temperature cannot be applied as such. This work is an exciting development towards a fully

• an energy much higher than the thermal energy, the quantum absorption mechanism is already realized, and the real absorption picture becomes much more complicated [19]. It is necessary to take into account many other parameters and relaxation mechanisms. An example of the thermalization process of a

• created. The process of electron energy relaxation continues until their characteristic times reach the tunneling time determined by the parameters of the SIN transition, that is, the transparency of the barrier, the thickness of the normal metal film, and the diffusion rate of electrons in it. For

Exploring the potential of polymers: advancements in oral nanocarrier technology

• Rousilândia de Araujo Silva,
• Igor Eduardo Silva Arruda,
• Luise Lopes Chaves,
• Mônica Felts de La Roca Soares and
• Jose Lamartine Soares Sobrinho

Beilstein J. Nanotechnol. 2025, 16, 1751–1793, doi:10.3762/bjnano.16.122

• . Release from nanospheres is generally governed by a combination of polymer degradation and drug diffusion through the matrix. Additionally, when hydrophilic polymers are employed, swelling-induced release becomes relevant, wherein polymer chain relaxation significantly influences the diffusion rate and

Multifunctional anionic nanoemulsion with linseed oil and lecithin: a preliminary approach for dry eye disease

• Niédja Fittipaldi Vasconcelos,
• Almerinda Agrelli,
• Rayane Cristine Santos da Silva,
• Carina Lucena Mendes-Marques,
• Isabel Renata de Souza Arruda,
• Priscilla Stela Santana de Oliveira,
• Mércia Liane de Oliveira and
• Giovanna Machado

Beilstein J. Nanotechnol. 2025, 16, 1711–1733, doi:10.3762/bjnano.16.120

• analysis. As the temperature rises, the double bonds in these unsaturated fatty acids undergo relaxation and changes from cis to trans configuration, distorting the molecular structure. This leads to weaker intermolecular interactions, which is reflected in a reduction in oil viscosity (as shown in Table 2

Modeling magnetic properties of cobalt nanofilms used as a component of spin hybrid superconductor–ferromagnetic structures

• Aleksey Fedotov,
• Olesya Severyukhina,
• Anastasia Salomatina and
• Anatolie Sidorenko

Beilstein J. Nanotechnol. 2025, 16, 1557–1566, doi:10.3762/bjnano.16.110

• magnetic behavior of the cobalt crystallite was considered in two stages. At the first stage (50 ps), relaxation of the system was performed, which resulted in mutual ordering of the spins of the atoms and orientation of the magnetization vector of the whole crystallite in some specific direction. At the

• second stage (10 ps), fluctuations of the magnetic values of the system stabilized after the relaxation stage were analyzed. For the stage of fluctuations of magnetic quantities, the graphs of changes in magnetic energy and reduced magnetization modulus (takes values from 0 to 1) of a cobalt crystallite

• moments from the initial random distribution of spins and subsequent relaxation within 50 ps. This stage was necessary to exclude the influence of initial conditions on the magnetic characteristics further investigated. In the second stage, the magnetic properties of the previously energetically

Influence of laser beam profile on morphology and optical properties of silicon nanoparticles formed by laser ablation in liquid

• Natalie Tarasenka,
• Vladislav Kornev,
• Alena Nevar and
• Nikolai Tarasenko

Beilstein J. Nanotechnol. 2025, 16, 1533–1544, doi:10.3762/bjnano.16.108

• -uniform energy distribution, which will affect plasma generation and confinement, the hydrodynamic trajectory of the ejected target material and pressure relaxation, as well as plasma and cavitation bubble propagation and temporal evolution. In the case of a Bessel beam, the focusing with an axicon

Single-layer graphene oxide film grown on α-Al₂O₃(0001) for use as an adsorbent

• Shiro Entani,
• Mitsunori Honda,
• Masaru Takizawa and
• Makoto Kohda

Beilstein J. Nanotechnol. 2025, 16, 1082–1087, doi:10.3762/bjnano.16.79

• the relaxation of the interfacial strains and the disappearance of wrinkles as seen in Figure 1b. Figure 3b shows the C K-edge NEXAFS spectra of SLG and SLGO. Two peaks P1 and P2 are observed at 285.4 eV and 287.5 eV. These peaks are assigned to the C 1s to π*(C=C) and to σ*(C–H) transitions

Time-resolved probing of laser-induced nanostructuring processes in liquids

• Maximilian Spellauge,
• David Redka,
• Mianzhen Mo,
• Changyong Song,
• Heinz Paul Huber and
• Anton Plech

Beilstein J. Nanotechnol. 2025, 16, 968–1002, doi:10.3762/bjnano.16.74

• many fields, such as heterogeneous catalysis [2][3], (bio)photonics [4], and coating or device fabrication [5]. In a bottom-up approach the products of the laser-based synthesis are not defined by direct spatial control, but by harnessing the energetic and structural relaxation pathways of fundamental

• early-time structural relaxation and chemical bond dynamics in laser-induced ionization of liquid water. In the third chapter “Nanoparticle excitation in an ensemble and energy exchange with medium”, an approach is shown on how reactions of both the excited NPs as well as the interaction with the

• surrounding liquid can be resolved in one experiment. And finally, a fourth chapter provides a state-of-the-art overview on the subject “Large-scale optical probing of laser ablation dynamics in liquids”. Here, the relaxation dynamics of a few tens of square micrometer large laser-excited surface, as used in

Shape, membrane morphology, and morphodynamic response of metabolically active human mitochondria revealed by scanning ion conductance microscopy

• Eric Lieberwirth,
• Anja Schaeper,
• Regina Lange,
• Ingo Barke,
• Simone Baltrusch and
• Sylvia Speller

Beilstein J. Nanotechnol. 2025, 16, 951–967, doi:10.3762/bjnano.16.73

• . This movement is likely driven by residual direct interaction forces or indirect hydrodynamic forces induced by the pipette’s hopping motion. Such tilting and subsequent relaxation can occur only during the pipette’s approach to or retraction from the mitochondrion. Additionally, the steep slope of the

Heat-induced transformation of nickel-coated polycrystalline diamond film studied in situ by XPS and NEXAFS

• Olga V. Sedelnikova,
• Yuliya V. Fedoseeva,
• Dmitriy V. Gorodetskiy,
• Yuri N. Palyanov,
• Elena V. Shlyakhova,
• Eugene A. Maksimovskiy,
• Anna A. Makarova,
• Lyubov G. Bulusheva and
• Aleksandr V. Okotrub

Beilstein J. Nanotechnol. 2025, 16, 887–898, doi:10.3762/bjnano.16.67

• sp3 hybridization is a metastable material. A significant activation barrier hampers its relaxation into sp2 graphitic carbon, and this transformation occurs during vacuum heating in the temperature range of 1500–1800 °C [9]. According to molecular dynamics simulations, graphitization of nonterminated

Ar⁺ implantation-induced tailoring of RF-sputtered ZnO films: structural, morphological, and optical properties

• Manu Bura,
• Divya Gupta,
• Arun Kumar and
• Sanjeev Aggarwal

Beilstein J. Nanotechnol. 2025, 16, 872–886, doi:10.3762/bjnano.16.66

• surface relaxation process, which leads to the smoothening of the surface and is also mentioned as negative surface tension by others [32][33]. This process causes the breaking of larger structures into smaller ones. Thus, one can tune the surface morphology of films using an inert ion beam through a

• fluences, the density of electronic excitation increases, and covalent bonds in the lattice are weakened. This leads to relaxation, which causes surface smoothening. The stoichiometry of pristine and implanted samples evaluated using EDS analysis are shown in Table 6. Because of the native oxide layer on

Changes of structural, magnetic and spectroscopic properties of microencapsulated iron sucrose nanoparticles in saline

• Sabina Lewińska,
• Pavlo Aleshkevych,
• Roman Minikayev,
• Anna Bajorek,
• Mateusz Dulski,
• Krystian Prusik,
• Tomasz Wojciechowski and
• Anna Ślawska-Waniewska

Beilstein J. Nanotechnol. 2025, 16, 762–784, doi:10.3762/bjnano.16.59

• relaxation processes observed for ferric carboxymaltose are also reported [9]. Conversely, ferrous gluconate, according to [10], exhibit paramagnetic behavior, and the possibility of a short-range magnetic order at low temperatures is only suggested, which means that the iron ions are sufficiently well

• the gathered data plotted as lnτ(ΤΜΑΧ−1) dependence, the below relaxation model was fitted [32]: where τ = f−1, kB is the Boltzmann constant, τ0 is the characteristic relaxation time, and EA is the activation energy of a nanoparticle. The fit gave the value τ0 ≈ 6.8 × 10−12 s, which is in the

Efficiency of single-pulse laser fragmentation of organic nutraceutical dispersions in a circular jet flow-through reactor

• Tina Friedenauer,
• Maximilian Spellauge,
• Alexander Sommereyns,
• Verena Labenski,
• Tuba Esatbeyoglu,
• Christoph Rehbock,
• Heinz P. Huber and
• Stephan Barcikowski

Beilstein J. Nanotechnol. 2025, 16, 711–727, doi:10.3762/bjnano.16.55

• inorganic IrO2 [14] based on shock wave formation caused by stress confinement. The conditions for stress confinement are fulfilled if the pulse duration is shorter than the acoustic relaxation time and thus a maximum pressure increase occurs in the particle. For curcumin and CBD, this is the case with a

• pulse duration of 10 ps (as the acoustic relaxation time is higher, tac, 1 µm ≥ 500 ps, Equations S11 and S12, Supporting Information File 1). Depending on the optical penetration depth, the particle size influences whether homogeneous or inhomogeneous heating takes place. The heated volume leads to the

• , and (II) differences in the MP dissociation pathways, which may hinder the formation of the desired SMPs and NPs when educt particles are too large. For both MP material systems we confirmed, based on the calculation of the acoustic relaxation time, that the stress confinement condition for the use of

N₂⁺-implantation-induced tailoring of structural, morphological, optical, and electrical characteristics of sputtered molybdenum thin films

• Usha Rani,
• Kafi Devi,
• Divya Gupta and
• Sanjeev Aggarwal

Beilstein J. Nanotechnol. 2025, 16, 495–509, doi:10.3762/bjnano.16.38

• microstructure and the interplay of intrinsic and extrinsic stress mechanisms. Figure 4 shows that the tensile stress in as-deposited Mo thin films decreases from 1.25 to 0.31 GPa as the film thickness increases from 150 to 300 nm, attributed to the relaxation of intrinsic stress induced during deposition. At

• volume, enhancing the cumulative distortion effects inside the films. Furthermore, nitrogen implantation improves densification and modifies the crystal structure. Nitrogen ions serve as a barrier in boundary relaxation and grain growth, hence increasing the stress. The divergent behavior illustrates the