Journal of Applied Physics最新文献

{"title":"Natural frequency informed finite element modal analysis method for estimating elastic properties of solid materials","authors":"Sanjay Mahat, Roshan Sharma, Hyunjo Jeong, Jingfei Liu","doi":"10.1063/5.0231087","DOIUrl":"https://doi.org/10.1063/5.0231087","url":null,"abstract":"This study proposes a simple yet effective dynamic method that can nondestructively evaluate the elastic properties of homogeneous isotropic solid materials. Like some dynamic methods, such as resonance ultrasound spectrometry and impulse excitation technique, the proposed method consists of two steps: experimentally acquiring the specimen's natural frequencies and numerically calculating the elastic properties. Compared with the existing methods, the proposed method has much lower requirements on all four aspects of experimental operations: specimen preparation, specimen positioning, vibration excitation, and vibration detection. An inverse method based on finite element modal analysis is proposed to calculate the specimen's elastic properties, and it can deliver optimal estimations with high precision and accuracy. The performance of the proposed method was assessed using the well-established sound speed-based dynamic method, i.e., ultrasound pulse-echo testing. Taking a square aluminum specimen as an example, the differences in the measurements of Young's modulus and Poisson's ratio between these two methods are 2.25% and −2.07%, respectively; the differences in the measurements of shear modulus and bulk modulus are 0.01% and −1.46%, respectively. In summary, the proposed method provides a cheaper and experimentally simpler approach to determining the elastic properties of solid materials while maintaining accuracy and reliability similar to the established methods, which typically require sophisticated, costly equipment.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"25 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Features of the formation of hot dense plasma in X-pinches on current generators based on low-inductive capacitors","authors":"T. A. Shelkovenko, I. N. Tilikin, A. R. Mingaleev, V. M. Romanova, S. A. Pikuz","doi":"10.1063/5.0220763","DOIUrl":"https://doi.org/10.1063/5.0220763","url":null,"abstract":"The paper presents the results of experimental studies of the operation of hybrid X-pinches on a modified high-current KING generator. The KING generator is a portable pulse current generator based on four low-inductive pulse capacitors. The output assembly of the generator was modified for greater diagnostic access to the load, which led to an increase in the inductance of the entire circuit and an increase in the duration of the current rise. A series of experiments with hybrid X-pinches with Al, Cu, and Mo wires with a diameter of 25 μm was carried out on the modified KING generator (200–260 kA, 220–280 ns, 45 kV). In experiments, it was shown that such a modification of the generator led to the stable formation of bright soft x-ray sources in X-pinches, suitable for use in point-projection radiography with a spatial resolution of about 10–15 μm.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"35 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Effects of irradiation damage on the hardness and elastic properties of quaternary and high entropy transition metal diborides","authors":"Amey Khanolkar, Amit Datye, Yan Zhang, Cody A. Dennett, Weiming Guo, Yang Liu, William J. Weber, Hua-Tay Lin, Yanwen Zhang","doi":"10.1063/5.0206224","DOIUrl":"https://doi.org/10.1063/5.0206224","url":null,"abstract":"Multi-principal component transition metal (TM) diborides represent a class of high-entropy ceramics (HECs) that have received considerable interest in recent years owing to their promising properties for extreme environment applications that include thermal/ environmental barriers, hypersonic vehicles, turbine engines, and next-generation nuclear reactors. While the addition of chemical disorder through the random distribution of TM elements on the cation sublattice has offered opportunities to tailor elastic stiffness and hardness, the effects of irradiation-induced structural damage on the physical properties of these complex materials have remained largely unexplored. To this end, changes in the hardness and elastic moduli of a high-entropy TM diboride (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)B2 and three of its quaternary subsets following irradiation with 10 MeV gold (Au) ions to fluences of up to 6 × 1015 Au cm−2 are investigated at the micrometer and sub-micrometer length-scales via the dispersion of laser-generated surface acoustic waves (SAW) and nanoindentation, respectively. The nanoindentation measurements show that the TM diborides exhibit an initial increase in hardness following irradiation with energetic Au ions, with a subsequent decrease in hardness following further irradiation. One quaternary composition, (Hf1/3Ta1/3Ti1/3)B2, exhibits a notable exception to the trend and continues to exhibit an increase in hardness with ion irradiation fluence. Although differences in the absolute values of the effective elastic moduli obtained from the measured SAW dispersion and nanoindentation are observed (and attributed to microstructural variations at the measurement length-scale), both techniques yield similar trends in the form of an initial reduction and subsequent saturation in the elastic modulus with increasing ion irradiation fluence. The quaternary TM diboride (Hf1/3Ta1/3Ti1/3)B2 again exhibits a departure from this trend. The high-entropy TM diboride (Hf0.2Nb0.2Ta0.2Ti0.2Zr0.2)B2 exhibits the greatest recovery in hardness and modulus when irradiated to high ion fluences following initial changes at low fluence, indicating superior resistance to radiation-induced damage over its quaternary counterparts. Opportunities for designing HECs with superior hardness and modulus for enhanced radiation resistance (compared to their single constituent counterparts) by tailoring chemical disorder and bond character in the lattice are discussed.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"8 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Permittivity enhancement of Al2O3/ZrO2 dielectrics with the incorporation of Pt nanoparticles","authors":"Bao Zhu, Ze Shang, Chenyan Wang, Xiaohan Wu, David Wei Zhang","doi":"10.1063/5.0218456","DOIUrl":"https://doi.org/10.1063/5.0218456","url":null,"abstract":"Al2O3/ZrO2 (A/Z) layers with embedded Pt nanoparticles (Pt-nps) at the interface of A/Z have been used to create a dielectric film with an enhanced permittivity. The Pt-nps and dielectrics are both grown by the atomic layer deposition process, which is complementary metal–oxide–semiconductor compatible. In order to control the thickness ratio of Pt-nps in the overall dielectrics more easily, the thickness of the ZrO2 layer is changed from 12 to 30 nm with a fixed thickness of 12 nm for Al2O3 and constant growth cycles of 70 for Pt-nps. The results show that the introduction of Pt-nps is beneficial to the enhancement of the dielectric permittivity. As the thickness of ZrO2 is 30 nm, the capacitance density increases from 2.5 to 5.1 fF/μm2 with the addition of Pt-nps, i.e., a doubling of the capacitance density achieved. Additionally, the leakage current at 2 V increases from 1.1 × 10−8 to 1.5 × 10−7 A/cm2. Furthermore, the dielectric breakdown field decreases from 5.4 to 2.7 MV/cm. The electric field distribution simulation and charging–discharging test imply that interfacial polarization is built at the interface of Pt-nps and the dielectric films, which contributes to the dielectric permittivity enhancement, and local electric field increasing in the affinity of Pt-nps gives rise to the deterioration of the leakage current and breakdown electric field.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"9 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Minimization of detent force in PMLSM by end magnetic regulating module with free topologies","authors":"Xiaozhuo Xu, Kai Hua, Haichao Feng, Siyuan Jiang, Yunji Zhao","doi":"10.1063/5.0232229","DOIUrl":"https://doi.org/10.1063/5.0232229","url":null,"abstract":"In this paper, a novel method for suppressing the detent force of permanent magnet linear synchronous motors is proposed. First, the end force is adjusted to offset the cogging force while the cogging force remains unchanged. On the other hand, the proposed method can arbitrarily change the shape of the end magnetic regulating module (EMRM), thus allowing the end force to obtain a wider adjustment range, which is different from the conventional limited shape optimization. More interestingly, compared to the traditional approach for suppressing the end force, which is to suppress the end force to the lowest level, the proposed method does not necessarily suppress the end force to the lowest level, but rather adjusts it to a reasonable level, so that it can offset the cogging force. This leads to the fact that the optimized end magnetic regulating module is effective in adjusting the end force and may even increase the end force, which is different from the conventional idea of suppressing the detent force. Next, the optimal EMRM's topologies are solved using the optimization algorithm, which replaces the traditional low-dimensional single-direction optimization and performs multi-direction global search. Finally, the prototype with optimal EMRM's topology and the testing platform are established and the experimental results validate the effectiveness of the proposed method.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"21 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Magnetic tunnel junctions with superlattice barriers","authors":"Jing-Ci Su, Shih-Hung Cheng, Sin-You Huang, Wen-Jeng Hsueh","doi":"10.1063/5.0228748","DOIUrl":"https://doi.org/10.1063/5.0228748","url":null,"abstract":"The urgent demand for high-performance emerging memory, propelled by artificial intelligence in internet of things (AIoT) and machine learning advancements, spotlights spin-transfer torque magnetic random-access memory as a prime candidate for practical application. However, magnetic tunnel junctions (MTJs) with a single-crystalline MgO barrier, which are central to magnetic random-access memory (MRAM), suffer from significant drawbacks: insufficient endurance due to breakdown and high writing power requirements. A superlattice barrier-based MTJ (SL-MTJ) is proposed to overcome the limitation. We first fabricated the MTJ using an SL barrier while examining the magnetoresistance and resistance-area product. Lower writing power can be achieved in SL-MTJs compared to MgO-MTJs. Our study may provide a new route to the development of MRAM technologies.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"63 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142226121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Theoretical prediction of chalcogen-based Janus monolayers for self-powered optoelectronic devices","authors":"Yuxuan Sun, Naizhang Sun, Wenlin Zhou, Han Ye","doi":"10.1063/5.0223915","DOIUrl":"https://doi.org/10.1063/5.0223915","url":null,"abstract":"Exploring potential two-dimensional monolayers with large photogalvanic effect (PGE) has been of great importance for developing self-powered optoelectronic devices. In this paper, we systematically investigate the generation of PGE photocurrent in chalcogen-based Janus XYZ monolayers (X/Y/Z = S, Se, Te; X ≠ Y ≠ Z) based on non-equilibrium Green's function formalism with density functional theory. The optimized Janus SSeTe, SeSTe, and TeSeS monolayers in the rectangular phase are shown stable and, respectively, possess 1.54, 1.49, and 1.74 eV indirect bandgaps. Illuminated by linearly polarized light, the PGE photocurrent without bias voltage can be collected in both armchair and zigzag directions. Unlike common Janus 2D materials with C3v symmetry, the photocurrent peak values of Janus XYZ monolayers do not come up with certain polarization angles, while the relations can be fitted by Iph = α sin(2θ) + β cos(2θ) + γ at each photon energy. Meanwhile, the maximum photoresponses of Janus SSeTe, SeSTe, and TeSeS monolayers are 2.02, 3.33, and 4.42 a20/photon, respectively. The relatively large PGE photocurrents and complicated polarization relations result from the lower symmetry of Janus XYZ monolayers. Moreover, the specific polarization angles for maximum photoresponses at each photon energy and the ratio between two transport directions are demonstrated, reflecting the anisotropy. Our results theoretically predict a potential Janus monolayer family for self-powered optoelectronic applications.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"43 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Influence of local structure and metal-oxygen hybridization on the electrical and magnetic properties of alkaline earth metal (Mg2+, Ca2+, Sr2+) substituted LaFeO3 ceramics","authors":"Subhajit Nandy, Mya Theingi, Sayan Ghosh, Keun Hwa Chae, C. Sudakar","doi":"10.1063/5.0222233","DOIUrl":"https://doi.org/10.1063/5.0222233","url":null,"abstract":"Pristine and alkaline-earth metal-substituted LaFeO3 (La1−xAxFeO3−δ; x = 0 and 0.2; A = Mg2+, Ca2+, and Sr2+) sintered ceramics are prepared from nanoparticles synthesized via a low-temperature citrate sol–gel technique. X-ray diffraction studies confirm the formation of a phase-pure LaFeO3 structure without any secondary phases for all the La1−xAxFeO3−δ compositions. LaFeO3 and La0.8Mg0.2FeO3−δ ceramics show Raman active modes related to La vibration, oxygen octahedral tilting, bending, and stretching. The optical bandgap is estimated to be 2.34 eV for pure LaFeO3 and reduces to 2.23 eV for La0.8Mg0.2FeO3−δ ceramics. On the contrary, La0.8Ca0.2FeO3−δ and La0.8Sr0.2FeO3−δ ceramics show no features in Raman spectra, consistent with the observation of metallic nature and diffuse band edge without any indication of sharp band edge noted. X-ray absorption spectroscopy (XAS) studies on La-L3 and Fe-K-edges confirm the oxidation states of La3+ and Fe3+ in all these ceramics. Local structural distortions and formation of oxygen vacancies in La0.8A0.2FeO3−δ (A = Mg2+, Ca2+, and Sr2+) ceramics are discerned from XAS structure analysis compared to the pristine LaFeO3 ceramics. Magnetic measurements of La1−xAxFeO3−δ reveal weak ferromagnetic nature except for La0.8Mg0.2FeO3−δ, which shows a large magnetization of 4.6 (6.7) emu/g at 300 (5) K. The ferromagnetic behavior of La0.8Mg0.2FeO3−δ ceramics seems to originate from the modification of hybridization between Fe(3d)–O(2p), La(5d)–O(2p), and Fe(4sp)–O(2p) orbitals. An anomalous magnetic transition observed only in zero-field-cooled curves at 88 K in La0.8Ca0.2FeO3−δ and La0.8Sr0.2FeO3−δ ceramics is correlated to the formation of new electronic states containing O 2p character as discerned from pre-peak O-K-edge.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"2 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Light narrowing over broad temperature range with paraffin-coated vapor cells","authors":"Shuyuan Chen, Xingqing Jin, Wentian Xiang, Wei Xiao, Changping Du, Xiang Peng, Hong Guo","doi":"10.1063/5.0230602","DOIUrl":"https://doi.org/10.1063/5.0230602","url":null,"abstract":"This study reports light narrowing in paraffin-coated vapor cells from room temperature 27 to 59 °C, where spin-exchange relaxation is suppressed. By means of a coating lock and eliminating the reservoir effect, an ultra-narrow magnetic resonance linewidth of 0.36 Hz and an atomic coherence lifetime of T2=0.9 s are achieved. In cells free of buffer gas, the narrow linewidth over this broad temperature range is a result of enhanced spin polarization, which is facilitated by the effective suppression of radiation trapping benefiting from the stability of the vapor density. Using such cells in atomic magnetometers, the photon shot noise limit is estimated as 0.2 fT/Hz1/2 and the spin-projection noise limit is estimated as 1.1 fT/Hz1/2. Also, a magnetometer system with the stable coated cell is identified, which demonstrates the potential for achieving relatively stable magnetometer sensitivity without precisely controlling the cell temperature. The long coherence lifetime and the broad operating temperature range expand the potential applications of quantum memory and other quantum sensors such as atomic clocks.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"26 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Characterizing polarization switching kinetics of ferroelectric Hf0.5Zr0.5O2 at cryogenic temperature","authors":"Jiacheng Xu, Rongzong Shen, Haoji Qian, Gaobo Lin, Jiani Gu, Jian Rong, Huan Liu, Yian Ding, Miaomiao Zhang, Yan Liu, Chengji Jin, Jiajia Chen, Genquan Han","doi":"10.1063/5.0218693","DOIUrl":"https://doi.org/10.1063/5.0218693","url":null,"abstract":"We have characterized polarization switching kinetics of Hf0.5Zr0.5O2 (HZO) at cryogenic temperature (T) down to 100 K. By the nucleation-limited-switching model with Lorentzian distribution fittings, the dependences of the average switching time (log τ1) and switching time distribution (ω) on T are extracted. As T decreases from 300 to 100 K, log τ1 first rapidly decreases and then gradually stabilizes. Meanwhile, ω exhibits different trends under different external electric fields (Eext), decreasing under low Eext while increasing under high Eext, eventually stabilizing at non-zero constants. With the further decrease in T (<100 K), log τ1 and ω exhibited by HZO are almost unchanged, indicating the intrinsic properties of ferroelectric multiple domains, which are different from the prediction in previous literature studies that log τ1 and ω will linearly decrease as T decreases.","PeriodicalId":15088,"journal":{"name":"Journal of Applied Physics","volume":"3 1","pages":""},"PeriodicalIF":3.2,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142204280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}