Rare Earth Er Research Articles

Effect of rare earth Er on discontinuous precipitation and mechanical properties of Cu-15Ni-8Sn-0.3Fe alloy

The Cu-15Ni-8Sn-0.3Fe-xEr (wt%, x = 0.1–0.4) alloy was prepared by vacuum induction melting. The microstructure evolution, mechanical properties and discontinuous precipitation (DP) growth kinetics during solidification and heat treatment were systematically investigated. The results show that the added Er leads to the formation of micrometer-sized ErNiSn2 phase and nanometer-sized ErNi phase in the Cu-15Ni-8Sn-0.3Fe alloy, which suppresses the formation of the discontinuous precipitation phases. Compared to alloys with other compositions, the Cu-15Ni-8Sn-0.3Fe-0.3Er alloy exhibits superior mechanical properties during aging at different temperatures. Specifically, after aging for 13 h at 723 K, the alloy achieved a peak hardness of 383.5 HV. In addition, the growth kinetics of the DP in Cu-15Ni-8Sn-0.3Fe-xEr (wt%, x = 0.1–0.4) alloys were evaluated using the Johnson-Mehl-Avrami-Kolmogorov equation. The activation energy (Q) of DP in the Cu-15Ni-8Sn-0.3Fe-0.3Er alloy is 178.4 kJ/mol, which is 39.2 kJ/mol higher than that of the Cu-15Ni-8Sn alloy.

Rare earths and other elements content in hen eggs sold in Italy: comparison among main types of farming methods and consumer's health risk assessment.

Recently, in Italy, consumers are choosing hen eggs from farming systems with higher ethical value, due to their perception of a related higher quality and safety. The purposes of this study were to evaluate the existence of differences in elemental content in Italian eggs from organic, barn, and caged hen farming methods and to determine the related potential consumer exposure risk to inorganic contaminants due to the consumption of eggs. One hundred seventy-six egg samples were collected and analyzed using Q-ICP-MS to investigate the content of 14 elements (Pb, As, Hg, Cd, Tl, Fe, Zn, Mn, Cu, Se, Co, Ni, V, and Cr) and 13 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb). The scenarios of exposure to rare earth and other elements from eggs were estimated for three age groups of consumers. The daily intake values were always lower than the respective safety reference values. In conclusion, Italian hen eggs contain low levels of rare earth and other elements, and therefore, their consumption does not represent a risk of exposure. Finally, no significant differences in contaminants between conventional and organic farming methods were found.

Boosting the sonophotocatalytic performance of BiOCl by Eu doping: DFT and an experimental study

Bismuth oxychloride (BiOCl) has a unique layered structure and uneven charge distribution, resulting in an internal electric field under polarization, which promotes the efficient separation and migration of photogenerated carriers. BiOCl could be a candidate for sonophotocatalysts. However, the low utilization of visible light limits the application of BiOCl in photocatalysts. In this study, the photocatalytic performance of rare earth element (Nd, Sm, Eu, Er and Er)-doped BiOCl was studied by density functional theory (DFT) and experimentally to screen high-performance catalysts. The band structure, density of states, and optical properties were calculated by the DFT method to predict the photocatalytic activity of rare earth-doped BiOCl. The built-in electric field formed in Eu-doped BiOCl inhibiting electron and hole recombination can be observed. Subsequently, the activity of the photocatalyst and sonophotocatalysts was evaluated. The results show that the photocatalytic and sonophotocatalytic activity of Eu-doped BiOCl is improved, which is consistent with the theoretical prediction. Combining theoretical calculations with experiments, the sonophotocatalytic activity of Eu-doped BiOCl is enhanced, mainly due to the synergistic effect of inhibiting carrier recombination, and expansion to the visible light absorption region.

Low-cycle Fatigue Behavior and Microscopic Morphology of Fatigue Crack Structure of Al-Cu-Ag-Fe-Mg-Zr-Er Alloy in The Aging Treatment

Al-Cu-Ag-Fe-Mg-Zr-Er alloy with different content of Er addition was prepared by using metallurgy processing. The Al-4.5%Cu-0.5%Ag-0.35%Fe-0.38%Mg-0.1%Zr-xEr alloy phase and its refinement mechanism were studied with SEM. Tensile and fatigue tests were performed for the alloy in the state of deformation treatment condition. The microstructural observations reveal that the addition of 0.2% rare earth Er can effectively refine the grain structure of Al-Cu-Ag-Fe-Mg-Zr-Er alloy. It improves room temperature tensile strength, yield strength, and elongation at break. Under the condition of low cycle fatigue loading, Al-4.5%Cu-0.5%Ag-0.35%Fe-0.38%Mg-0.1%Zr-0.2%Er alloy shows a cyclic strain hardening in the cyclic stress response curves, which mainly depends on forming complex dislocation configurations. The accumulation of slip bands at the front of the grain boundary will lead to intergranular fracture of the material.

Preparation of a novel Ti/TNAs/PbO2-PVDF-Er2O3 anode by Ti3+ self-doping TNAs and its electrocatalytic performance for hydroquinone degradation

A new type of Ti/TNAs/PbO2-PVDF-Er2O3 electrode was prepared in this research via composite electrodeposition method with Ti3+ self-doped modified titanium dioxide nanotubes arrays (TNAs) as the intermediate layer, and co-deposition of PVDF and rare earth Er (Ⅲ) into PbO2, which is expected to be used for efficient degradation of hydroquinone (HQ) wastewater. The research results indicate that the Ti/TNAs/PbO2-PVDF-Er2O3 electrode is composed of more compact β-PbO2, possesses the largest hydrophobicity (97.8°) among the series electrodes. Additionally, the electrode exhibits remarkable electrocatalytic performance with the largest oxygen evolution potential (2.012 V), the largest electrochemical active surface area (ECSA), and the smallest electron transfer resistance (1.054 Ω·cm2). Furthermore, the Ti/TNAs/PbO2-PVDF-Er2O3 electrode is used for the degradation of HQ, and the experiments results reveal that the degradation process is mainly controlled by the indirectly oxidation of ·OH generated on the surface of the electrode, which is presumed to be oxidized to benzoquinone and various fatty acids by ·OH in combination with GC-MS, and finally mineralized to CO2 and H2O. Meanwhile, under the optimum degradation conditions (pH:7, temperature: 30 ℃, Na2SO4: 0.1 M, current density: 50 mA.cm‐2), the degradation rate is up to 94.5%, demonstrating the best electrocatalytic degradation efficiency.

Nd-Mn Molecular Cluster with Searched Targets for Oral Cancer Imaging.

In this research, we designed a novel NIR II luminescence imaging probe with targeting effect to accurately track oral squamous cell carcinoma (OSCC) cells. Massive gene expression data were processed by weighted gene co-expression network analysis to establish a network of relationships between genes. After clustering, correlation of clinical information, and gene functional enrichment analysis, MMP1 was predicted to be a biomarker/therapeutic target for OSCC cells. To obtain rare-earth probes with better luminescence in the NIR II region, we adjusted the doping ratio of the rare-earth element (Nd, Gd, Er, and Yb) fraction of the Nd-Mn molecular cluster to optimize its luminescence properties. The results of in vitro targeting experiments showed that Nd-Mn-MMP1Ab can target Cal-27 cells, demonstrating at the cellular level that the MMP1 gene is a biomarker for oral cancer, which also proves that the cancer targets predicted by the bioinformatics approach are correct.

Magnetostrictive improvement in Er-doped biodegradable Fe81Ga19 alloys manufactured by selective laser melting

In this study, rare earth Er was introduced into magnetostrictive Fe–Ga alloys by selective laser melting (SLM) technique for the first time in order to tailor the microstructure and thereby the magnetostrictive properties. The results showed that the rapid solidification of SLM process not only retained the disorder phases but also promoted the solid solution of partial Er into Fe–Ga matrix which increased the lattice parameters. Moreover, the rest of Er distributed at the grain boundaries along the temperature gradient and prevented the lateral expansion of matrix grains, leading to columnar grains with preferred orientation in {100} direction. Consequently, the magnetostriction coefficient of the Er-doped Fe81Ga19 alloys was improved up to 92 ppm with an Er content of 0.6 at.%, representing a 40% enhancement compared to Fe81Ga19 alloy. But excessive Er resulted in the formation of GaEr intermetallic phase, which was adverse to Ga–Ga pair structure and magnetostriction. The Fe81Ga19Er0.6 alloy also presented acceptable cytocompatibility and slightly accelerated degradation due to the galvanic corrosion between Er phase and Fe–Ga matrix. These findings indicated the potential of the Er-doped Fe81Ga19 alloys prepared by SLM as future magnetostrictive implants in biology and medicine.

The electrical, and photosensitive behavior of diodes with rare earth elements (Yb and Er) doped sodium yttrium fluoride interfacial layer

This study presents the morphological, electrical, and photosensitive behavior properties of the Al/(NaYF 4 :Yb,Er)/p-Si structure. The (NaYF 4 :Yb,Er) used as an interfacial layer was deposited on a p-Si semiconductor using the thermal evaporation method. The surface morphological properties of the evaporated interfacial layer were examined using scanning electron microscopy and atomic force microscopy. The ideality factor of the structure increases from 3.58 at 320 K to 8.16 at 100 K with decreasing temperature, while the barrier height decreases from 0.80 eV at 320 K to 0.31 at 100 K with decreasing temperature in the same temperature range. The photosensitive behavior of the fabricated structure were investigated using UV-A lamp with 350 nm wavelength. The spectral responsivity, photosensitivity, and detectivity values for the Al/(NaYF 4 :Yb,Er)/p-Si structure were found to be 0.525 A.W−1, 2841.38, and 2.16 × 1011 Jones, respectively.

Phase Stability and Dual-Mode Photoluminescence Modulation in Er-Doped Lead Zirconate Titanate Antiferroelectrics.

The electric-field-modulation (E-modulation) of photoluminescence (PL) properties in bulk ceramics has attracted tremendous interest due to its potential application in optical data storage and communication devices. One promising approach of reversibly and largely modulating the PL intensity has been proposed in rare-earth Er3+-doped Pb0.96La0.04Zr0.9Ti0.1O3 (PLZT) antiferroelectrics (AFEs) based on the unique E-dependent antiferroelectric-ferroelectric (AFE-FE) phase transition. However, the AFE phase stability of PLZT doped with various Er contents and their E-modulated PL properties have not been systematically investigated. In this paper, the intrinsic AFE phase of PLZT-Er is found to be stabilized in the high-temperature and high-E regions with increasing Er3+ content. The enhanced AFE nature caused by increasing Er doping leads to a larger E-dependent PL tunability (∼35%). Moreover, the ceramics exhibit the characteristics of both upconversion and downconversion PL (UCPL and DCPL) effects. Based on the excellent E-dependent dual-mode PL tunability, an optoelectronic device named the optical latch is demonstrated, where an electric signal can be used to trigger a notable intensity change in both the UCPL and DCPL modes. This reversible E-dependent dual-mode capability in PLZT-Er sheds light on a feasible approach to optoelectronic applications.

Fabrication of a novel PbO2 electrode with rare earth elements doping for p-nitrophenol degradation

A novel PbO2 electrode modified with rare earth elements (La, Ce, Gd and Er) doping (named as Re-PbO2) was prepared by electrodeposition in the present study. The micro-morphology and crystal structure of Re-PbO2 were characterized by scanning electronic microscopy (SEM), energy dispersive spectroscope (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. Their electrochemical properties were determined by linear sweep voltammetry (LSV), cyclic voltammetry (CV), accelerated life test and hydroxyl radicals (•OH) formation analysis. Electrochemical oxidation of p-nitrophenol (p-NP) by Re-PbO2 compared with un-doped PbO2 has been investigated and the degradation rate followed the order of Er-PbO2 > Gd-PbO2 > La-PbO2 > Ce-PbO2 > PbO2. Especially for Er-PbO2, the pseudo-first order kinetic for p-NP (kp-NP) degradation was 0.41, which was only 0.19 for un-doped PbO2. Rare earths elements doping improved the oxidation ability of Re-PbO2 mainly through reducing grain size, increasing oxygen evolution potential, enlarging electrochemical active surface area and enhancing •OH formation ability. In addition, existing formation of oxygen species on PbO2 electrode surface was investigated by XPS. For Re-PbO2, percentage of lattice oxygen species (Oads) were higher than that on the un-doped one. These results demonstrated that rare earth elements can enhance the oxidation ability of PbO2 electrode significantly.

Achieving strength and ductility synergy via a nanoscale superlattice precipitate in a cast Mg-Y-Zn-Er alloy

Precipitation strengthening is one of the most promising methods to develop magnesium (Mg) alloys. However, the nerve-wracking fact is that the cast Mg alloys always have coarse second particles, which inevitably leads to a poor ductility. In this study, a novel nanoscale superlattice precipitate (NSP) with a superior strengthening effect is developed by rare-earth Er alloying. The newly-developed cast Mg-Y-Zn-Er alloy possesses a yield strength of 154 MPa, a tensile strength of 234 MPa, and a total elongation of ∼ 13%. The NSPs is systematically investigated, using transmission electron microscopy and first-principles calculations. The NSP with an average radius of 4 nm has a five periodic supercell structure enriched with Zn, Y, and Er atoms. The first-principles calculations indicate that Zn, Y, and Er atoms are apt to segregate on the (112¯1) plane. The excellent strength is contributed mainly by the ordering strengthening of the NSPs. The addition of Er enhances the multiplication of dislocations and the activation of 〈c + a〉 dislocation system during deformation, contributing to the ductility.

Effects of Cu/Er on Tensile Properties of Cast Al-Si Alloy at Low Temperature.

The current protocol presents the effects of the addition of Cu, rare earth Er, and Cu-Er composite elements on the microstructure of the Al-10Si-0.3Mg alloy. The variations in their low-temperature tensile properties were also investigated. The addition of rare earth Er elements, Cu elements, and Cu-Er composite elements increased the strength of all three groups of alloys when stretched at low temperatures (-60 °C). Further, the elongation of the alloy increased with the addition of Er, while the elongation of the other two groups decreased. The low-temperature (-60 °C) tensile strength of the alloy with the same composition was higher than that at room temperature (20 °C), but the elongation decreased. Notably, by adding rare earth Er to the Al-10Si-0.3Mg alloy, the three-dimensional morphology was changed from coarse dendritic to fine fibrous, the secondary dendritic arm spacing (SDAS) of the alloy was reduced, and the grains were refined. The Al2Cu phase, Al-Si-Cu-Mg quaternary phase, and Cu-rich phase appeared in the alloy with the addition of Cu elements, but the Si phase morphology and α-Al dendrites were not significantly improved. Interestingly, the Si phase morphology of the alloy was improved by adding Cu-Er composite elements, and SDAS was reduced. Still, the Al2Cu phase, Al-Si-Cu-Mg quaternary phase, and Cu-rich phase were not much improved.

Enhanced piezoelectricity and non-contact optical temperature sensing performance in Er3+ ion modified (K,Na)NbO3-based multifunctional ceramics

Rare earth ions doped ferroelectrics have attracted wide attentions due to their multifunction characteristics with both ferroelectric/piezoelectric properties and intriguing photoluminescence performance, which show great prospects for future multifunctional devices. In this work, a novel rare earth Er3+ ion modified potassium-sodium niobate (KNN) based ceramics were elaborately designed and prepared by the conventional solid-state reaction. The microstructure, phase structure, electric properties and photoluminescence performance of the Er3+ ion modified KNN-based ceramics were systematically investigated. Enhanced piezoelectricity (a considerable d33 of exceeding 300 pC/N and a large d33* up to 500 p.m./V) was realized through optimizing the substitution of BaZrO3 by (Er0.5,Na0.5)ZrO3. Both down-conversion and up-conversion photoluminescence emissions were detected in the optimal composition. The temperature-dependent upconversion emissions of the optimal Er3+ modified ceramic sample in the temperature range of 303–573K were verified to be applicable for non-contact optical temperature sensing with a maximum sensitivity Sa of 0.0028 K-1 and a peak relative sensitivity Sr of 0.96% K−1. Moreover, low-temperature sensing performance with a maximum Sr of 16.7% K−1 in the temperature range of 80–280K was also presented based on the temperature-dependent down-conversion emissions. With both decent electrical properties and intriguing photoluminescence performance, the Er3+-modified KNN-based ferroelectrics exhibit good application potential in the future multifunctional optoelectronic devices.

The coupling strengthening effect of in situ nanoparticles and rare earth in AA6111 matrix composites

Differed from the traditional aluminum alloy enhanced by single strengthening phase, a new design of AA6111–3ZrB2-0.3Er-0.1Zr composites reinforced by in situ ZrB2 nanoparticles and Er, Zr was proposed in this work. The coupling effect includes two aspects: the distribution of ZrB2 particles has been significantly improved by rare earth Er and the strain field on surface of ZrB2 particles intensified the precipitation behavior of Al3(Er, Zr). Besides, contributed by the coupling effect of these two different strengthening phases, a fine and uniform DRXed grain structure was obtained after hot extrusion. The YS (Yield Strength), UTS (Ultimate Tensile Strength) and EL (Elongation) of as-extruded AA6111–3ZrB2-0.3Er-0.1Zr composites at room temperature and 573 K were high up to 372.8 MPa, 420.5 MPa, 30.6% and 135.3 MPa, 156.7 MPa, 46.7% respectively. The coupling strengthening effect was always stronger than that strengthened by single ZrB2 particles or Al3(Er, Zr) precipitates. What’s more, both ZrB2 particles and Al3(Er, Zr) precipitates with core-shell structure belong to thermal stable phases, which was exactly the main reason why AA6111–3ZrB2-0.3Er-0.1Zr composites could maintain the prominent performances even in high temperature environment.

Effect of Ce and Er doping on crystal morphology and mechanical properties of dental restoration material Li2O-Al2O3-SiO2 glass ceramics

This study is to investigate the effect of Ce and Er doping on the mechanical properties of Li2O-Al2O3-SiO2 system glass-ceramics. Orthogonal test was used to explore the formulation of dental lithium disilicate glass-ceramics with the best mechanical properties. On this basis, rare earth elements Ce and Er were doped to investigate the effect of doping on the crystal morphology and mechanical properties of glass-ceramics, and the chemical stability of the doped samples was evaluated. Through many experiments, the optimal raw material composition for preparing Li2O-Al2O3-SiO2 glass-ceramics was determined as follows: Li:Si 76:24, NH4H2PO4 3%, Al2O3 10%, and K2CO3 3%, The highest hardness is 672 MPa and the highest fracture toughness is 306 MPa. The doping results show that a certain amount of Ce or Er on the surface can make the matrix glass grow into radial flake or lamellar crystals. Radial crystals can improve the fracture toughness of glass-ceramics, but reduce its hardness. The hardness of laminated crystal glass ceramics increases, but the bending strength decreases.

Differentiation of Transylvanian fruit distillates using supervised statistical tools based on isotopic and elemental fingerprint.

The spirit drinks industry is one of the largest in the world. Fruit distillates require adequate analysis methods combined with statistical tools to build differentiation models, according to distinct criteria (geographical and botanical origin, producer's fingerprint, respectively). Over time a database of alcoholic beverage fingerprints can be generated, being very important for product safety and authenticity control. To control the distillates' geographical origin, linear discriminant analysis (LDA) revealed that the cross-validation classification was correct for 88.2% of samples, but partial least squares discriminant analysis (PLS-DA) was slightly better suited for this purpose, with a correct classification rate of 91.2%. LDA effectiveness was proven for the trademark fingerprint differentiation, which was achieved at 93.5%, compared to 89.1% for PLS-DA. The principal predictors obtained by LDA were the same both for geographical origin and producer differentiation: B, δ13 C, Na, Cu, Ca and Be; highlighting the fact that in the production process of distillates each producer used fruits coming from the respective specific region. Through PLS-DA, some of the discrimination markers were the same for geographical origin and producer's identification, but others were completely specific: the rare earth elements Eu and Er only for geographical origin differentiation, and Cu solely as predictor for producer's identification. Regarding distillates' fruit variety, the correct discrimination rates of plum spirits from the rest were 84.2% for PLS-DA and 63% for LDA. LDA and PLS-DA were suitable for differentiation models development of fruits spirits according to geographical region, producer and fruit variety based on isotopic and elemental fingerprint. © 2022 Society of Chemical Industry.

The third biological window luminescence for tissue penetration through Cr–Er energy transfer

A series of near-infrared broadband luminescent phosphors LiScGeO4:0.007Cr, Er3+ were prepared by the high temperature solid-state method, and the energy transfer from Cr ions to rare earth Er3+ ions was realized. Co-doping of Cr and Er makes up for the luminescence of LiScGeO4:Cr at 1531 nm and improves the luminescence intensity at NIR-III biological windows, (1500–1800 nm). By co-doping rare earth ions, the thermal stability is improved, which is beneficial to the application of phosphor-converted light emitting diodes (pc-LED). Finally, the packaged pc-LED penetrates the fingers and leaves, showing its good penetration ability.

Role of Er on the densification, microstructure and mechanical properties of 7075 aluminium alloys manufactured by laser powder bed fusion

Fabricating crack-free 7075 aluminium alloy by laser powder bed fusion (LPBF) is currently a hot research topic. In this work, pre-alloyed 7075Al + Er powder was prepared, and crack-free samples were printed by LPBF by adjusting the process parameters. Furthermore, the influence of process parameters and the mechanism of crack inhibition by Er were discussed. Er can generate Al3Er coherent with the Al matrix, which has the grain refinement effect, shortens the length of columnar crystals from 106 μm to 84 μm and is conducive to the dispersion and further solidification of the liquid film in the paste solidification stage. Al3Er also reduces the texture strength and makes the thermal stress more uniform. The final measured tensile strength of the printed sample was 338 MPa, and the elongation was 15.9%, which was 32% and 74.7% higher than those of the 7075Al samples without Er addition, respectively. In this work, the effect of rare earth element Er on the improvement of the printability and crack suppression of 7075 aluminium alloy by laser powder bed fusion was discussed, which provides experimental support for crack-free additive manufacturing and application of high-strength aluminium alloys.

(Electronics and Photonics Division Award) Let There be Light; Research at the Intersection of Electronics and Photonics

Electronics and photonics have a long and successful history of combining to provide many devices and products that are at the heart of the modern technological world, ranging form solar cells to lasers to digital displays. In this presentation I will first give a brief historical overview of the interplay and interdependence of electronics and photonics. The properties and effects that are commonly exploited in opto/electronics fall primarily in two areas: (a) the effect of incident light (or more generally radiation) due to optical absorption/transmission/reflection and the conversion of photons to electrical charge that can be collected; (b) the injection of electrons & holes leading to the emission of photons. Then I will review selected examples from my research in optoelectronic materials and devices in more or less chronological order over the past 40+ years. An early example [1] in the light-to-charge was integration of infrared detectors using narrow bandgap semiconductors (such as InSb and HgCdTe) with silicon charge coupled devices that performed data storage and image processing functions on arrays of pixels. A major research topic in my group in the charge-to-light category has for many years been electroluminescence [2] from wide bandgap semiconductors (primarily GaN and AlN) doped with rare earth elements (Er, Eu, Tm, etc.). Narrow linewidth emission can occur at wavelengths from near UV to visible to IR, depending on the electronic transitions of the selected RE element and the bandgap of the host material. In the past 10 years, my materials interest switched from inorganic to organic semiconductors and biomaterials, but with a continuing strong opto/electronic component. Currently, a major research focus is in developing simple, low cost and intuitive diagnostic devices for point-of-care use. These devices analyze the composition of biofluids (e.g. blood, sweat, saliva, etc.) to provide a 1st order indication of specific aspects the individual’s health status, such as blood coagulation, stress, etc. The use of light in PoC and other diagnostic devices is widespread. Most common and simplest approach is colorimetric detection in ambient light, where a change of color in a region of the device indicates the presence of a specific biomolecule associated with a given medical condition. Somewhat more complex diagnostic devices use fluorescence of molecules attached to biomarkers to indicate their presence. In our own research, biofluid samples are typically transported by capillary flow to a location where their key properties are measured by a combination of optical emission [3], transmission and absorption [4]. The presentation will conclude with a look forward to other applications where photonics and electronics could join forces.[1] A.J. Steckl, et al., “Application of Charge Coupled Devices to Infrared Detection and Imaging,” Proc. of IEEE, 63(1), 67, Jan 1975 ( doi.org/10.1109/PROC.1975.9708 ).[2] (a) A.J. Steckl and J.M. Zavada, “Optoelectronic Properties and Applications of Rare-Earth-Doped GaN”, Mat. Res. Soc. Bulletin, 24(9), 33, Sep 1999 doi.org/10.1557/S0883769400053045; (b) A. J. Steckl, et al., Invited Paper, “Rare-earth-doped GaN: Growth, Properties and Fabrication of Electroluminescent Devices”, IEEE J. Selected Topics in Quantum Electronics, 8 (4), 749 Jul 2002 doi.org/10.1109/JSTQE.2002.801690 [3] V. Venkatraman and A. J. Steckl, “Quantitative Detection in Lateral Flow Immunoassay Using Integrated Organic Optoelectronics”, IEEE Sensors, 17 (24), 8343, Dec 2017 (doi.org/10.1109/JSEN.2017.2764178 ).[4] P. Ray and A. J. Steckl, “Label-Free Optical Detection of Multiple Stress Biomarkers in Sweat, Plasma, Urine and Saliva”, ACS Sensors 4, 1346, 2019. (doi.org/10.1021/acssensors.9b00301). Figure 1

Novel and environment-friendly high NIR reflectance color pigments based on Fe, Pr, Ho, Nd, Er and Ce doped lithium aluminum molybdate: Synthesis and properties

This paper reports the syntheses of a series of polychromatic pigments with the general formula LiAl1-xMx(MoO4)2 (M = Fe, Pr, Ho, Nd, Er, Ce; x = 0–0.4) and the characterization of near-infrared reflectance properties. The synthesized pigments exhibited green (Pr), lavender (Nd), pink (Er) and different yellows (Fe, Ho, Ce). The XRD patterns of typical LiAl1-xFex(MoO4+δ)2 samples show that the prepared samples are triclinic lithium aluminum molybdate structures with space group P-1.The iron in the sample mainly existed in the form of Fe3+, which led to the directional growth of grains with different morphologies. The near-infrared solar reflectance (R*%) of LiAl1-xFex(MoO4)2 pigments reached 94.19%. As the doping concentration of rare earth was increased, the color of the pigments gradually deepens. By introducing rare earth elements Pr, Ho, Nd, Er, and Ce into the LiAl(MoO4)2 matrix, the color of the pigment was successfully changed from white to green, lavender, pink, and yellow, indicating that doping can control the color of the pigment. Moreover, the prepared pigments had high R*% (>87%), indicating that the pigment samples have excellent thermal insulation properties and can be used as a new type of reflective thermal insulation coatings.