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Retraction of 'Growth factors regional patterned and photoimmobilized scaffold applied to bone tissue regeneration' by Ling-Kun Zhang et al., J. Mater. Chem. B, 2020, 8, 10990–11000, https://doi.org/10.1039/D0TB02317E. [ABSTRACT FROM AUTHOR]

Zero-dimensional perovskites have received extensive attention in recent years due to their unique structural properties, including large exciton binding energies, strong quantum confinement effects, and good stability. Target products were precisely constructed from existing organic–inorganic hybrid perovskite material phase-transition systems via exploiting the ideas of molecular design, modification, and assembly. Herein we report an organic–inorganic hybrid perovskite compound, [C6H18F6N3SbBr6] (1), with excellent reversible phase transition and dielectric switching properties. The symmetry of the structure was reduced upon introducing fluorine atoms to the ethylamine moiety. The results showed that compound 1 had a narrow bandgap of 2.90 eV and three distinct dielectric anomalies at ∼175.9, 205.9, and 257.5 K. UV-vis absorption spectra and density-functional theory (DFT) calculations confirmed this bandgap. It was revealed that the octahedral framework of inorganic [SbBr6]3− was the main contributor to this bandgap. This work highlights that the substitution of hydrogen atoms by halogens has important effects on the structural phase transition mechanism and physical properties of the synthesized product, therefore, it provides an effective strategy for the synthesis of novel organic–inorganic hybrid perovskite phase-transition materials. [ABSTRACT FROM AUTHOR]

Piezoelectric responsive molecular ferroelectrics have become a research hotspot due to their advantages of simple fabrication, environmental friendliness, light weight and good mechanical flexibility. Here we proposed a new kind of multipole rare earth molecular ferroelectric, ((nBu)4N)3[Ce(NO3)4(SCN)2]((CH3CH2CH2CH2)4N = tetrabutylammonium) (1). Compound 1 undergoes a high temperature ferroelectric phase transition at 408 K. It is worth noting that compound 1 has a narrow band gap of 2.61 eV, flexible switchable SHG effect, moderate spontaneous polarization Ps = 3.6 μC cm−2, and piezoelectric constant = 3 pC N−1. The results show that these findings provide ideas for exploring multifunctional rare earth molecular ferroelectrics with a piezoelectric effect. [ABSTRACT FROM AUTHOR]

Bistable switches (electrical switching between "ON" and "OFF" bistable states) have gradually developed into an ideal category of highly intelligent materials, due to their significant applications in optical technology, signal processors, data storage and other switchable media applications in the field of electrical devices. Here, we successfully designed and synthesized [(FC6H4C2H4NH3)2MCl4]n(FC6H4C2H4NH3+)=deprotonated 4‐fluoro‐ phenethylamine; M=Cd (1), Mn (2)), which realized the coupling of thermo‐dielectric switching characteristics, semi‐conductor characteristics and photo‐luminescent properties. DSC (differential scanning calorimetry) and dielectric measurements show that 1 is a sensitive dielectric bistable switch between the high dielectric (ON) and low dielectric (OFF) states. The temperature‐variable single crystal structure shows that the both 1 and 2 undergo a high‐temperature reversible phase transition around 383 K/380 K, which is caused by the order‐disordered transformation of organic cations and the slight distortion of the inorganic framework. In particular, 1 shows outstanding switchable dielectric behavior and semiconducting properties. Further, 1 and 2 emit strong green and yellow luminescence at 527 and 595 nm, respectively. [ABSTRACT FROM AUTHOR]

The tetracyanopyridine (4-cyanopyridine and 3-cyanopyridine) was reacted with rare earth nitrates (Ln = La, Gd, Er) under hydrothermal conditions by the Demko-Sharpless method, and four rare earth tetrazolium ionic compound were synthesized safely and effectively, named [Ln(H2O)8 ⋅ 3(p-TPD) ⋅ 2(p-HTPD) ⋅ 7H2O], (Ln = La( 1), Gd(2), Er (3), p-TPD = 4-tetrazolpyridine), [Ln(H2O)8 ⋅ 3(m-TPD) ⋅ 6H2O], (m-TPD = 3-tetrazolpyridine, Ln = Er(4)). These four rare earth tetrazolium ionic compounds were characterized by the single crystal X-ray diffraction, infrared spectroscopy, thermogravimetry, dielectric properties, X-ray powder diffraction. The X-ray single crystal structure analysis shows that the four rare earth tetrazolium compounds were all ionic, and the rare earth metal ions and ligands were in two different layers. The [Ln(H2O)8]3+ structure unit and p-TPD and water molecules formed a cationic layer through hydrogen bonding, while p-TPD and p-HTPD formed an anion layer through π-π stacking and hydrogen bonding. The cation layer and anion layer alternately form a regular network structure. Moreover, the dielectric properties tests indicate that the compounds 1, 2 have good dielectric properties. [ABSTRACT FROM AUTHOR]

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been widely used for in situ microanalysis of elemental concentrations in solid samples, but its application is hampered by a lack of matrix-matched and homogeneous reference materials (RMs). In this work, a new method for preparing matrix-matched and homogeneous LA-ICP-MS reference materials has been developed. A multiple rare earth element (REE) doped CaWO4 single crystal (CaW-1) was successfully prepared by the Czochralski technique. The matrix composition and crystal structure were confirmed by X-ray diffraction (XRD) and electron microprobe analysis (EMPA), which indicates that these crystals have a matrix composition of CaWO4 and are matrix-matched with natural scheelite. The homogeneity of REE distribution was systematically studied by seven methods and the results demonstrated that REEs are distributed homogeneously in the CaWO4 single crystal with slight fluctuation (RSDs: ca. 4%). It can be concluded that the synthesized CaWO4 single crystal meets both crucial requirements, matrix-matched and homogeneous distribution, for an LA-ICP-MS reference material, and therefore it was used to quantitatively calibrate REE concentrations in natural scheelite. The results showed that acceptable analytical errors (<8%) were obtained, which were more desirable than those obtained with non-matrix-matched NIST SRM 610 as the RM. It robustly validates the ability of the developed method for preparing CaWO4 single crystals as possible LA-ICP-MS reference materials to calibrate REE concentrations in natural scheelite. [ABSTRACT FROM AUTHOR]

Electroplating additives play a key role in enhancing the physical and chemical performances of electrodeposited copper foils. Currently, a lot of research on polyethylene glycol (PEG) additives has been reported on the metallisation interconnections for printed circuit boards (PCBs); however, research on its applications for electrodeposited copper foils is rarely documented. Herein, high-quality copper foils with high tensile strength (433.2 MPa) and low surface roughness (Rz = 1.7 μm) were electrodeposited on titanium substrates with 4 mg L -1 PEG. The characterization results showed that the copper foil possesses a high (220) crystal plane orientation and low twin layer thickness. Further analysis suggested that twin boundaries strengthened by stacking faults were the main reason for the high tensile strength of copper foils. Electrochemical behavioral studies indicated that PEG increased the cathodic polarization and improved the nucleation rate, thereby refining the copper foil grain size. The high (220) crystal plane orientation and high density of twin grain boundaries caused by the stacking faults strengthened the copper foil more than the fine-grain strengthening. This work offers theoretical guidance for modulating the properties of copper foil using PEG., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)