Non‐Ising‐like 180° ferroelectric domain wall architecture and domain distribution in tetragonal PbZrxTi1−xO3 thin films are probed using a combination of optical second harmonic generation and ...scanning transmission electron microscopy. In the remnant state, a specific nonlinear optical signature of tilted 180° domain walls corresponding to a mixed Ising–Néel‐type rotation of polarization across the wall is shown.
Hexagonal manganites are among the most intensively studied multiferroics, exhibit unusual geometrically driven ferroelectricity and magnetoelectric couplings, and form domains and domain walls with ...intriguing functional properties. In order to study these electronic correlation phenomena and develop a comprehensive understanding about the underlying physics, the availability of high-quality single-crystals is crucial. In particular, different members of the RMnO3 (R=Sc, Y, In, Dy to Lu) family require different growth condition in order to achieve stoichiometric single-phase crystals. Here, we report on the growth of high-quality ErMnO3 single crystals with dimensions of 5mm in diameter and up to 60mm in length using the pressurized floating-zone technique. We present Laue diffraction, piezoresponse force microscopy, and conductive atomic force microscopy data, reflecting the quality of our single crystals regarding the structure, as well as electronic properties on the level of domains and domain walls.
•High-quality hexagonal ErMnO3 single-crystals are grown by the pressurized floating-zone method.•The growth pressure is up to 0.8MPa in any step of the growth.•The method effectively prevents the volatilization of manganese from melt during crystal growth and hence makes it possible to grow stoichiometric single crystals.•The piezoresponse force microscopy, and conductive atomic force microscopy data, reflected the quality of our single-crystals regarding the structure, as well as electronic properties on the level of domains and domain walls.
We investigate the effect of chemical doping on the electric and magnetic domain pattern in multiferroic hexagonal ErMnO3. Hole- and electron doping are achieved through the growth of Er1−xCaxMnO3 ...and Er1−xZrxMnO3 single crystals, which allows for a controlled introduction of divalent and tetravalent ions, respectively. Using conductance measurements, piezoresponse force microscopy and nonlinear optics we study doping-related variations in the electronic transport and image the corrsponding ferroelectric and antiferromagnetic domains. We find that moderate doping levels allow for adjusting the electronic conduction properties of ErMnO3 without destroying its characteristic domain patterns. Our findings demonstrate the feasibility of chemical doping for non-perturbative property-engineering of intrinsic domain states in this important class of multiferroics.
Morphotropic phase boundary (Bi1/2Na1/2)TiO3–(Bi1/2K1/2)TiO3 (BNT–BKT), was modified with increasing additions of Bi(Zn1/2Ti1/2)O3 (BZT). Microstructure, electric‐field‐induced strain and ...polarization, dielectric permittivity, and temperature‐dependent piezoelectric coefficient were investigated and compared with crystal structure measured in situ as a function of applied electric field. Furthermore, permittivity and piezoelectric coefficient were characterized as a function of electric field. For small additions of BZT, an applied electric field leads to an irreversible phase transition into a ferroelectric phase with remanent polarization and a reduced relative permittivity. Increasing the content of BZT increased the threshold field for the transition. For additions of more than 2 mol% BZT, the piezoelectric coefficient dropped, permittivity remained almost constant, and a high normalized strain of up to 500 pm/V was observed. However, no field‐dependent structural change was evidenced by the in situ X‐ray experiment.
Insulin-like growth factor 1 (IGF1) is an important biomarker for the management of growth hormone disorders. Recently there has been rising interest in deploying mass spectrometric (MS) methods of ...detection for measuring IGF1. However, widespread clinical adoption of any MS-based IGF1 assay will require increased throughput and speed to justify the costs of analyses, and robust industrial platforms that are reproducible across laboratories. Presented here is an MS-based quantitative IGF1 assay with performance rating of >1,000 samples/day, and a capability of quantifying IGF1 point mutations and posttranslational modifications. The throughput of the IGF1 mass spectrometric immunoassay (MSIA) benefited from a simplified sample preparation step, IGF1 immunocapture in a tip format, and high-throughput MALDI-TOF MS analysis. The Limit of Detection and Limit of Quantification of the resulting assay were 1.5 μg/L and 5 μg/L, respectively, with intra- and inter-assay precision CVs of less than 10%, and good linearity and recovery characteristics. The IGF1 MSIA was benchmarked against commercially available IGF1 ELISA via Bland-Altman method comparison test, resulting in a slight positive bias of 16%. The IGF1 MSIA was employed in an optimized parallel workflow utilizing two pipetting robots and MALDI-TOF-MS instruments synced into one-hour phases of sample preparation, extraction and MSIA pipette tip elution, MS data collection, and data processing. Using this workflow, high-throughput IGF1 quantification of 1,054 human samples was achieved in approximately 9 hours. This rate of assaying is a significant improvement over existing MS-based IGF1 assays, and is on par with that of the enzyme-based immunoassays. Furthermore, a mutation was detected in ∼1% of the samples (SNP: rs17884626, creating an A→T substitution at position 67 of the IGF1), demonstrating the capability of IGF1 MSIA to detect point mutations and posttranslational modifications.
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