Shengyi Liu , Shang Gao , Duan Gao , Li Wang , Wenbin Song , Han Yin , Ying Zhu , Jingjing Zhang , Qianmiao Yu , Xin Chen
{"title":"Up-conversion phosphor LaCaGaO4: Er3+/Yb3+ for the optical temperature sensing and anti-counterfeiting","authors":"Shengyi Liu , Shang Gao , Duan Gao , Li Wang , Wenbin Song , Han Yin , Ying Zhu , Jingjing Zhang , Qianmiao Yu , Xin Chen","doi":"10.1016/j.cap.2025.03.001","DOIUrl":"10.1016/j.cap.2025.03.001","url":null,"abstract":"<div><div>Successfully synthesized LaCaGaO<sub>4</sub>: Er<sup>3+</sup> and LaCaGaO<sub>4</sub>: Er<sup>3+</sup>/Yb<sup>3+</sup> phosphors via high-temperature solid-state reactions and thoroughly investigated their up-conversion luminescence properties under 980 nm and 1550 nm excitation. X-ray diffraction analysis confirmed the phase purity of the materials, and up-conversion luminescence measurements demonstrated emissions in the visible and near-infrared regions, primarily at 530 nm, 550 nm, 670 nm, and 810 nm, corresponding to Er<sup>3+</sup> transitions. Mechanistic studies revealed that under 980 nm excitation, both green and red emissions are two-photon processes, while under 1550 nm excitation, these emissions are driven by three-photon processes. Co-doping with Yb<sup>3+</sup> enhanced luminescence intensity, with an increase in the red-to-green emission ratio as the Yb<sup>3+</sup> concentration increased. Furthermore, these materials exhibited excellent temperature sensing capabilities, with fluorescence intensity ratios from thermally coupled energy levels showing good agreement with the Boltzmann distribution. Maximum sensitivities S<sub>A</sub><sup>MAX</sup> of 0.00054 K<sup>-1</sup> (980 nm excitation) and 0.00632 K<sup>-1</sup> (1550 nm excitation) were achieved, highlighting their potential for applications in optical thermometry, color tuning, and anti-counterfeiting.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 84-97"},"PeriodicalIF":2.4,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143610322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Pedagogical approach to anomalous position and velocity","authors":"Younsik Kim , Suk Bum Chung , Changyoung Kim","doi":"10.1016/j.cap.2025.03.003","DOIUrl":"10.1016/j.cap.2025.03.003","url":null,"abstract":"<div><div>In this work, we discuss a pedagogical method in deriving the expressions for anomalous position and velocity. While we follow the steps used in optics in the derivation of the group velocity, we use Bloch wave functions instead of plane wave states. In comparison to the plane wave case, application of Bloch wave functions results in two additional terms in the expression of the group velocity: the Berry phase factor and anomalous position contributions. These two new terms with distinct origins eventually lead to the known anomalous velocity. Aiming for an intuitive understanding, we simulate the situation under an electric field using linear-combination-of-atomic-orbital states and visually demonstrate that the envelope function exhibits the transverse motion expected from an anomalous velocity.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 112-116"},"PeriodicalIF":2.4,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancement of barrier protection of organic coatings with the incorporation of graphene oxide as a reinforcing filler","authors":"Sachin Sharma Ashok Kumar , K. Ramesh , S. Ramesh","doi":"10.1016/j.cap.2025.03.004","DOIUrl":"10.1016/j.cap.2025.03.004","url":null,"abstract":"<div><div>Graphene and its derivatives, such as graphene oxide (GO) are new materials with unique properties which have been widely employed as a reinforcing filler material in organic coatings. The superior properties of GO, such as its large surface area, surface wettability, stability, chemical resistance, and high mechanical strength, have resulted the GO material to be a promising additive in anti-corrosion coatings. On the other hand, due to the presence of oxygen-containing functional groups, the GO has exhibited high water dispersibility. In addition, the chemical functionalization that is facilitated by these functional groups on the GO surface resulted in the enhancement of dispersibility and corrosion protection performance. Hence, the GO-based polymer coatings have attracted significant attention globally especially in the corrosion industry. Although, the electrochemical characteristics of GO-polymer nanocomposite coatings have not been explored much. Therefore, in this study, a series of coatings were developed by incorporating various amounts of GO nanoparticles into the polymer matrix. These coatings were then coated on the steel substrates and the barrier protection performance of GO-based coatings was investigated using electrochemical impedance spectroscopy (EIS). In addition, the electrochemical activity was observed by determining the breakpoint frequencies (<span><math><mrow><msub><mi>f</mi><mi>b</mi></msub></mrow></math></span>) over a period of 90 days. The results revealed that the incorporation of GO nanoparticles significantly enhanced the corrosion protection performance of the coatings. The results demonstrated that the best corrosion resistance was achieved by the 0.5 % GO coating sample. Fourier transform infrared (FTIR) spectroscopy was employed to verify the chemical structure of the composite coatings.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 98-111"},"PeriodicalIF":2.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Siham Koriche , Abdelkader Khalfallah , Hiba Azzeddine , Thierry Baudin , François Brisset , Yi Huang , Terence G. Langdon
{"title":"Self-annealing behavior of an Mg-Dy alloy processed by high-pressure torsion","authors":"Siham Koriche , Abdelkader Khalfallah , Hiba Azzeddine , Thierry Baudin , François Brisset , Yi Huang , Terence G. Langdon","doi":"10.1016/j.cap.2025.02.010","DOIUrl":"10.1016/j.cap.2025.02.010","url":null,"abstract":"<div><div>An investigation was conducted to evaluate the microstructure, texture and microhardness of an Mg-0.4Dy (wt.%) alloy processed by high-pression torsion (HPT) for 15 turns and then self-annealed at ambient temperature for six years. Electron backscatter diffraction (EBSD) and Vickers microhardness were carried out near the centre, mid-radius and edge of each disc. The results show that self-annealing leads to a slight increase in the average grain size from 0.7 to 1 μm. The basal texture was retained at the centres and edges of the discs while the <em>C</em><sub><em>1</em></sub>-fiber vanished near the mid-radius of the self-annealed disc. The value of the microhardness remained constant along the radii of the discs but the dislocation density, originating from the geometrically necessary dislocations (GND), increased significantly after self-annealing due to the development of sub-grain boundaries with misorientations of 2°< θ < 5°. Based on these results, it is concluded that self-annealing of the HPT-processed Mg-0.4Dy alloy is controlled by a recovery process.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 41-48"},"PeriodicalIF":2.4,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synthesis of Cu2O/ZnO fiber heterojunction networks for self-powered visible-light photodetectors with rapid response","authors":"Yiran Wang , Senzhuo Xing , Nan Zhang","doi":"10.1016/j.cap.2025.03.002","DOIUrl":"10.1016/j.cap.2025.03.002","url":null,"abstract":"<div><div>The network-based self-powered photodetector features a large interfacial area, enhancing light absorption and charge carrier generation, along with its mechanical robustness, enabling integration into various applications. In this study, we propose a novel self-powered photodetector based on an AZO/ZnO/Cu<sub>2</sub>O/Ag network architecture, fabricated using electrodeposition and atomic layer deposition techniques. The fabricated photodetector exhibits a detection wavelength range extending from 390 nm to 780 nm at zero bias, covering the visible spectrum. With a maximum responsivity of 1.6 mA/W and a response time of 5 μs, the device showcases excellent sensitivity and rapid detection capabilities. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and optoelectronic performance testing were employed to analyze the operating mechanism of the photodetector. It was found that the spatial charge region formed at the interface between Cu<sub>2</sub>O and ZnO layers plays a crucial role in enabling the self-powered operation of the photodetector. Our work provides a new strategy for the development of high-performance network photodetectors.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 77-83"},"PeriodicalIF":2.4,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Exploring bismuth ferrite: Structural changes and future applications","authors":"Swarupamayee Nayak , Pratiksha Agnihotri , Jagadis Prasad Nayak , Charul Joshi , Radheshyam Rai","doi":"10.1016/j.cap.2025.02.007","DOIUrl":"10.1016/j.cap.2025.02.007","url":null,"abstract":"<div><div>The review article provides a comprehensive quantitative analysis of bismuth ferrite (BiFeO<sub>3</sub>), focusing on its structural, electrical, and magnetic properties, as well as an extensive survey of the existing literature. Bismuth ferrite is a multifunctional material with significant potential for a range of technological applications, particularly in the fields of spintronics, energy harvesting, and memory devices. The review systematically examines various synthesis methods—including chemical vapor deposition, solid-state processes, sol-gel, and hydrothermal techniques—and their effects on the morphology, crystal structure, and overall properties of BiFeO<sub>3</sub>. The study highlights how specific fabrication techniques influence the material's ferroelectric and magnetic characteristics, exploring their implications for performance in diverse applications. By synthesizing findings from recent studies, this review aims to provide a quantitative understanding of how modifications to the material's structure impact its functionality, offering valuable insights for future advancements in the use of BiFeO<sub>3</sub> in advanced technologies.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 49-76"},"PeriodicalIF":2.4,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tunable plasmon-induced transparency based on graphene metasurface structure for mid-infrared sensing applications","authors":"Tae-Han Kim, Sang Woo Kim, Bo Wha Lee","doi":"10.1016/j.cap.2025.02.009","DOIUrl":"10.1016/j.cap.2025.02.009","url":null,"abstract":"<div><div>The plasmon-induced transparency (PIT) effect in graphene metasurface (MS) structures is investigated through numerical and theoretical analysis in the mid-infrared range. The unit cell of the MS consists of two vertical and one horizontal graphene strip. By adjusting the Fermi energy, a blue shift in the PIT window occurs, while changes in the surrounding medium's refractive index cause a red shift, enabling tunable PIT control without altering the structure. Theoretical models using coupled Lorentz oscillators show good agreement with the simulation results, revealing a slow-light effect through increased group delay. Sensitivity, Q-factor, and figure of merit (FOM) show that sensitivity ranges from 7.0 to 11 THz/RIU as the refractive index changes, and FOM reaches around 180 with stable Q-factor at 15. This work provides a physical understanding of the tunable PIT effect in graphene MS structures and suggests potential applications in sensing, selective filtering, and advanced refractive index-based detection.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 30-40"},"PeriodicalIF":2.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H.N.M. Sarangika , E.G.O.D. Egodawaththa , H.M.B.I. Gunathilaka , V.P.S. Perera , S. Ghosh , C. Bhattacharya
{"title":"Enhanced Photoelectrochemical performance by rapid electron transfer in reduced graphene oxide/CaWO4 composite photoanode","authors":"H.N.M. Sarangika , E.G.O.D. Egodawaththa , H.M.B.I. Gunathilaka , V.P.S. Perera , S. Ghosh , C. Bhattacharya","doi":"10.1016/j.cap.2025.02.006","DOIUrl":"10.1016/j.cap.2025.02.006","url":null,"abstract":"<div><div>Scheelite oxides and their derivatives are renowned for their exceptional stability, high photocatalytic efficiency, and versatile structural design, positioning them as a promising category of semiconductor photocatalysts. In this study, Scheelite calcium tungstate (CaWO<sub>4</sub>) films were fabricated on fluorine-doped tin oxide (FTO) substrates using the chemical bath deposition (CBD), followed by calcination. Graphene oxide (GO) was independently synthesized via the Hummers' method and subsequently deposited onto the CaWO<sub>4</sub> films through electrophoretic deposition (EPD) to form reduced graphene oxide/CaWO<sub>4</sub> (rGO/CaWO<sub>4</sub>) composites. The incorporation of rGO was found to play a crucial role in enhancing electron transport within the rGO/CaWO<sub>4</sub> films. In photoelectrochemical (PEC) water splitting, the rGO/CaWO<sub>4</sub> demonstrated a remarkable photocurrent of 13 μA cm<sup>−2</sup> at 1 V, far exceeding the 0.4 μA cm<sup>−2</sup> achieved by pristine CaWO<sub>4</sub> under identical conditions. This 32.5-fold enhancement in photocurrent is attributed to the rapid electron transfer facilitated by the rGO in the composite structure.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 22-29"},"PeriodicalIF":2.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Excitation wavelength dependent multiple biomolecule SERS responses from Bi/ZnO thin films towards ultrasensitive Hemoglobin and L-tyrosine detections","authors":"Risa Marium Philip, D. Bharathi Mohan","doi":"10.1016/j.cap.2025.02.008","DOIUrl":"10.1016/j.cap.2025.02.008","url":null,"abstract":"<div><div>Fabricated Bi/ZnO bilayer thin films enhances the surface plasmon coupling, creating a superhydrophobic Surface Enhanced Raman Scattering (SERS) platform. The excitation wavelengths, 532 and 785 nm were selected to balance the signal intensity and minimal fluorescence interference, towards improving the detection accuracy across a range of biomarkers from monomers to complex proteins. The films consist of columnar wurtzite ZnO base with orthorhombic metallic Bi on top. The minimal chemical changes at Bi: ZnO interface, confines the local electric field to surface. Cancer and neurodegenerative biomarkers, Hemoglobin (Hb) and L-tyrosine (Tyr), studied for Limit of Detection (LoD) using respective laser achieved, a 10 fM LoD with SERS enhancement factor (EF) of 8.42 x 10<sup>11</sup> for Hb (532 nm), and a 10 aM LoD with 6.60 x 10<sup>15</sup> SERS EF for Tyr (785 nm). These unprecedented detection thresholds demonstrate the ultrasensitive detection capabilities of the fabricated SERS platform for early medical diagnosis.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"73 ","pages":"Pages 1-21"},"PeriodicalIF":2.4,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanghyun Park , Jaeuk Baek , Min-Hwan Lee , Sanglok Lee , Geol Moon
{"title":"Long-term polarization stabilization of a polarization maintaining fiber via dynamic temperature control","authors":"Sanghyun Park , Jaeuk Baek , Min-Hwan Lee , Sanglok Lee , Geol Moon","doi":"10.1016/j.cap.2025.02.005","DOIUrl":"10.1016/j.cap.2025.02.005","url":null,"abstract":"<div><div>We achieved long-term polarization stabilization of the output beam obtained from polarization-maintaining (PM) fiber by feeding heat back to the fiber. Optical polarization stability is crucial in various fundamental and engineering fields, particulary in a miniaturized field-deployable system composed of optical components, such as cold-atom-based quantum sensors. We constructed a feedback loop to stabilize the polarization of the output beam of a PM fiber in thermal contact with a Peltier element. Notably, a long-term polarization stability against thermal fluctuations was achieved, and the characteristics of the thermal polarization stabilizer were analyzed based on the power spectral density, Allan deviation, and Bode plots. The results indicate that this system can effectively serve as a long-term intensity stabilizer and is ideal for use in laboratories in which PM fibers are widely used, but exact temperature regulation is not feasible.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"72 ","pages":"Pages 51-55"},"PeriodicalIF":2.4,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143396001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}