A new multianalyzer Bambus is being constructed at Panda, MLZ. The objective is to construct broad reciprocal space maps at multiple energy transfers, in order to get insights of broad features at low energy or study complex dispersion laws. Because this spectrometer is designed as a complementary option to the normal TAS mode, a fast switch between the two setups is foreseen. The general...
Over the last decades organic electronics (OE) have attracted the focus of research due to their advantageous properties. Advantages, such as the flexibility of OE, the ease of processablility and the applicability of industrial up-scalable and low-cost processing methods, open up a wide range of possible application fields. Especially organic photovoltaics (OPV) have drawn much attention, due...
Capillary breakup extensional rheomerty (CaBER) as a method for investigating short-time relaxation mechanisms and extensional properties of soft matter has immensely gained in importance since its invention almost 40 years ago. Despite its widespread use, this method has never been combined with high resolution in-situ structural investigations such as small angle scattering.
We demonstrate...
Latest research in the field of hybrid photovoltaics focuses on the benefits of inorganic and organic materials. Flexibility, low cost and large scale production are the most valuable properties of organic components whereas the inorganic components add chemical and physical stability. So far thin films based on titanium dioxide are well investigated, whereas less is known about...
We study the morphology, electric, magnetic, magneto-electric coupling
and magneto-transport properties of Fe$_3$O$_4$/Nb:SrTiO3(001) and
Fe$_3$O$_4$/PMN-PT(011) heterostructures. Studies like, interfacial capacitance,
magnetic depth profile, ferroelectric ordering, stress and charge
screening-control of the Verwey transition are of special interest. The
Fe$_3$O$_4$ films are grown in an oxide...
Due to limited supply of traditional fossil fuels, increasing carbon emission, and deteriorated environmental pollution, it is urgent for humankind to ensure alternative renewable energy sources. Because of high energy density, competitive working voltage, minimum self-discharge, and limited maintenance requirements, rechargeable lithium-ion batteries (LIBs) have been applied in various fields...
Due to low cost, flexibility, solution processing and large-scale fabrication, enormous attention is focusing on the research and development for higher OPV performance over the last decades. To improve the overall performance of organic photovoltaics, interfacial modifiers are widely applied in the device architecture to facilitate charge collection, tune the distribution of materials, and...
The investigation of thin polymer films with neutrons allows a non-destructive probe on their structure and composition. In the framework of the FlexiProb project, which plans an interchangeable sample environment for different neutron experiments at the European spallation source (ESS), we designed a setup for grazing incidence small angle neutron scattering (GISANS). The new sample chamber...
Although based on organic materials, organic solar cells often include metal electrodes due to their unrivaled electronic conductivity. Thus, polymer-metal interfaces are inherently present in most OPV devices and have a major influence on their behavior. Understanding the growth mechanisms of metal contacts on polymer thin films plays a crucial role in identifying potential ways to enhance...
The understanding of structure-property relationships is essential for the development and improvement of engineering materials. In-situ characterization of materials under external thermo-mechanical treatment is usually required. The materials science diffractometer STRESS-SPEC is designed to be applied equally to structure, texture and residual stress analyses by virtue of its very flexible...
Cell membranes play a fundamental role in protecting the cell from its surroundings, in addition to hosting many proteins with fundamental biological tasks. Drugs are able to perturb the structure of cell membranes, which can ultimately give rise to undesirable effects. Thus, a study of drug/lipid interactions is a necessary and important step in fully clarifying the role and action mechanism...
Bart-Jan Niebuur1, Geethu P. Meledam1, Vitaliy Pipich2, Marie-Sousai Appavou2,
Alfons Schulte3, and Christine M. Papadakis1
1 TU Mรผnchen, Physik-Department, Garching, Germany
2 FZ Jรผlich, JCNS at MLZ, Garching, Germany
3 University of Central Florida, Orlando, U.S.A.
The thermoresponsive polymer Poly(N-isopropylacrylamide) (PNIPAM) in aqueous solution forms dehydrated, smaller...
D. Gorkov a,b,c, G. Waldherr b, A. Grรผnwald a,b,c, J. Stein a, S. Giemsa c, P. Bรถni c, and M. Braden a
a II. Physikalisches Institut der Universitรคt zu Kรถln, D-50937 Kรถln, Germany.
b Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universitรคt Mรผnchen,
D-85747 Garching, Germany.
c Physik-Department E21, Technische Universitรคt Mรผnchen,
D-85747 Garching, Germany
KOMPASS is a polarized...
Alloys of rare-earth elements and 3d transition metals became recently again in the focus of attention due there rich variety of magnetic effects owed to the different anisotropies of both material classes [1-3].
In this work, various thin film systems containing the amorphous DyxCo100-x alloy will be discussed. Despite of their amorphous nature, the film system show non trivial magnetic...
Electronic skin (E-skin) as the medium between ambient environment and bionic robots is an advanced technology that provides an electronic readout or even produces a visualized response that can be easily captured for postprocessing. Since this concept birth, different electronic skins have been fabricated and utilized for various sensing applications, such as pressure, humidity, temperature...
NECTAR is a superior beam-line with access to fission neutrons for non-destructive inspection of large and dense objects, where thermal neutrons or X-rays face limitations due to their comparatively low penetration. With the production of fission neutrons at the instrument [1], as well as neutrons interacting with beamline geometry, such as the collimator, gamma rays are produced in the...
Organic-inorganic metal halide perovskite solar cells (PSCs) offer a potentially cheap source for clean and low cost electrical energy. Improving stability1, 2 and minimodule power conversion efficiencies over 17% in 20183 promise commercial devices possibly capable of competing with multi-crystalline silicon solar cells with current module efficiencies of around 22% in 20173. This calls for...
Photosynthesis is the key mechanism in utilization of solar radiation for living organisms and thus provides the base for most food chains and all fossil fuels. The functionality of photosynthetic proteins is -in part- critically influenced by dynamics on a timescale of pico- to milliseconds and on sub-nanometer length scale. The neutron time of flight spectrometer TOFTOF at MLZ-Garching is...
We report neutron scattering and AC magnetic susceptibility measurements of the 2D spin-1/2 frustrated magnet BaCdVO(PO4)2. At temperatures well below TN โ 1K, we show that only 34% of the spin moment orders in a up-up-down-down strip structure. Dominant magnetic diffuse scattering and comparison to published ฮผsr measurements indicates that the remaining 66% is fluctuating. This demonstrates...
An oxygen vacancy induced topotactic transition from perovskite to brownmillerite and vice versa in epitaxial La0.7Sr0.3MnO3-ฮด thin films is identified by real-time x-ray diffraction. A novel intermediate phase with a non-centered crystal structure is observed for the first time during the topotactic phase conversion which indicates a distinctive transition route. Polarized neutron...
Within the scope of this thesis, we modified and tested the new experimental set up for measuring Total Reflection High-Energy Positron Diffraction (TRHEPD [1]) and Reflection High-Energy Electron Diffraction (RHEED). The remoderated positron beam from NEPOMUC will be used for investigation of surface reconstructions with topmost atomic layer sensitivity.
In order to benchmark the RHEED...
The preparation of block copolymer (DBC) nanocomposite films that consist of magnetic nanoparticles (NPs) with diameters (D) of more than 10 nm is a challenging task. In the present work, this limitation is addressed by using an ultrahigh molecular weight (UHMW) DBC polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) as templates for the self-assembly of periodic hybrid materials...
We have studied superparamagnetic iron oxide nanoparticles by various experimental techniques in order to characterize the observed reduced saturation magnetization as compared to bulk. Magnetic nanoparticles of the size of 12 nm and 15 nm have been studied by means of small-angle X-ray scattering (SAXS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM),...
Nanostructured polymer-metal-composite films demonstrate great perspectives
for optoelectronic applications, e.g. as sensors or photovoltaics. To enhance properties of such devices the self-assembly process needs to be understood. We studied the cluster morphology growth by grazing incidence small-angle X-ray scattering (GISAXS), as well as the crystallinity of the metal film formation with...
A method for near surface strain scanning measurements using neutron diffraction with large gauge volumes is described and validated against x-ray diffraction (XRD) and neutron diffraction experiments with very high spatial resolution. The approach corrects for pseudo strains related to partially buried gauge volumes and enables to deconvolute the averaging effects associated with the use of a...
Recently organic lead mixed-halide perovskite based solar cells surpassed a power conversion efficiency of 22 %. In particular the unique properties of perovskites, e.g. the highly tunable chemical composition, allow optimizing the hybrid crystal structure in a way to meet the desired demands. To take full advantage of this tunability of the perovskite materials, we apply a 2-step deposition...
The rapid development of metal halide perovskite solar cells (PSCs) makes such solar cells power conversion efficiency (PCE) comparable with silicon solar cells and the certified PCE has already reached 23.7%1. However, long-term device stability is one of the most critical issues in PSCs. To improve the stability of PSCs, interface passivation, inorganic materials and encapsulation strategies...
Introduction
Due to their high melting point, low density, and good oxidation resistance, ฮณ-TiAl based alloys have recently started to replace Ni-based superalloys as a material for turbine blades in aircraft engines [1]. Conventional ฮณ -TiAl alloys usually contain the ordered phases ฮณ-TiAl and ฮฑ2-Ti3Al at lower temperatures and disordered ฮฑ-Ti(Al) phase above 1120ยฐC. Additional alloying...
The polymers poly(3-hexylthiophene), poly(3-thiopheneacetic acid), poly(3-thiopheneethanol) and the related copolymers are prepared starting from the respective monomer units by chemical oxidative polymerization. Graphene has also been oxidized to graphene oxide, which becomes due to the functionalization highly dispersible in organic solvents, forms far more homogeneous layers than pure...
Non-fullerene organic solar cells (OSCs) have attracted great interests due to the low cost materials, which make it easier to be commercialized in industries. Despite the power conversion efficiency (PCE) of related devices have been well developed with lab scaled fabrication processes, like spin-coating deposition, the situation for the devices fabricated by industry preferred depositions,...
Electronic skin (E-skin) as the medium between ambient environment and bionic robots is an advanced technology that provides an electronic readout or even produces a visualized response that can be easily captured for postprocessing. Since this concept birth, different electronic skins have been fabricated and utilized for various sensing applications, such as pressure, humidity, temperature...
