Pub Date : 2024-11-15DOI: 10.1016/j.cap.2024.11.009
Charu Dwivedi , Stuti Srivastava , Preetam Singh
We have studied the effect of film thickness (120, 180, and 286 nm) on the dual gas (NO & NO2) sensing performance of DC magnetron sputtered WO3 thin films deposited at room temperature. WO3 shows strong absorption from visible light to the infrared region. An unusual peak originates at 467.6 nm (film thickness 286 nm) instead of a broadband tail, usually found in WO3, which has been linked with oxygen vacancies. A high response of ∼196 at 150 °C for 50 ppm NO and ∼50 at 250 °C for 50 ppm NO2 is achieved for 286 nm film, which can be associated with Localized Surface Plasmon Resonance while a low response/recovery time of ∼39s/99s is obtained for 120 nm film at 200 °C for NO gas, which is its best operating temperature too (sensor response ∼100). Even under a high humidity (90 %) environment, the sensor detected 50 ppm of NO.
{"title":"Highly selective dual gas (NO & NO2) sensing depended on the operating temperature of WO3 thin films sputtered at room temperature","authors":"Charu Dwivedi , Stuti Srivastava , Preetam Singh","doi":"10.1016/j.cap.2024.11.009","DOIUrl":"10.1016/j.cap.2024.11.009","url":null,"abstract":"<div><div>We have studied the effect of film thickness (120, 180, and 286 nm) on the dual gas (NO & NO<sub>2</sub>) sensing performance of DC magnetron sputtered WO<sub>3</sub> thin films deposited at room temperature. WO<sub>3</sub> shows strong absorption from visible light to the infrared region. An unusual peak originates at 467.6 nm (film thickness 286 nm) instead of a broadband tail, usually found in WO<sub>3</sub>, which has been linked with oxygen vacancies. A high response of ∼196 at 150 °C for 50 ppm NO and ∼50 at 250 °C for 50 ppm NO<sub>2</sub> is achieved for 286 nm film, which can be associated with Localized Surface Plasmon Resonance while a low response/recovery time of ∼39s/99s is obtained for 120 nm film at 200 °C for NO gas, which is its best operating temperature too (sensor response ∼100). Even under a high humidity (90 %) environment, the sensor detected 50 ppm of NO.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 70-80"},"PeriodicalIF":2.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698212","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}
Pub Date : 2024-11-15DOI: 10.1016/j.cap.2024.11.007
Habeeb Olaitan Suleiman , Eun Young Jung , Hyojun Jang , Jae Young Kim , Heung-Sik Tae
Despite advancements in research on conducting polymers, obtaining stable conductivity in thin films remains challenging. Although ex-situ iodine (I2) doping methods have exhibited promise, they often result in unstable conductivity with increasing exposure time. This study aimed to produce polythiophene (PTh) nanostructure films with stable electrical conductivity through optimized ex-situ I2-doping techniques using a newly fabricated atmospheric pressure plasma reactor for PTh deposition. I2 charge carriers in the form of solid and liquid were separately incorporated into the PTh at room temperatures and 60 °C. FE-SEM, EDS, and FT-IR revealed an enhanced molecular structure, the distribution of element and functional chemical composition of the doped PTh nanostructure films, respectively. Compared to solid I2 doping, the liquid-doped PTh exhibited improved electrical conductivity and stable conductivity over a long period. The results also proved promising for reliable applications in electronic devices, making ex-situ liquid I2 doping a good technique.
{"title":"Comparison of ex-situ solid and liquid iodine doping methods at different temperatures to improve electrical properties of polythiophene nanostructure films synthesized by atmospheric pressure plasma process","authors":"Habeeb Olaitan Suleiman , Eun Young Jung , Hyojun Jang , Jae Young Kim , Heung-Sik Tae","doi":"10.1016/j.cap.2024.11.007","DOIUrl":"10.1016/j.cap.2024.11.007","url":null,"abstract":"<div><div>Despite advancements in research on conducting polymers, obtaining stable conductivity in thin films remains challenging. Although ex-situ iodine (I<sub>2</sub>) doping methods have exhibited promise, they often result in unstable conductivity with increasing exposure time. This study aimed to produce polythiophene (PTh) nanostructure films with stable electrical conductivity through optimized ex-situ I<sub>2</sub>-doping techniques using a newly fabricated atmospheric pressure plasma reactor for PTh deposition. I<sub>2</sub> charge carriers in the form of solid and liquid were separately incorporated into the PTh at room temperatures and 60 °C. FE-SEM, EDS, and FT-IR revealed an enhanced molecular structure, the distribution of element and functional chemical composition of the doped PTh nanostructure films, respectively. Compared to solid I<sub>2</sub> doping, the liquid-doped PTh exhibited improved electrical conductivity and stable conductivity over a long period. The results also proved promising for reliable applications in electronic devices, making ex-situ liquid I<sub>2</sub> doping a good technique.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"70 ","pages":"Pages 11-20"},"PeriodicalIF":2.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697804","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}
Pub Date : 2024-11-15DOI: 10.1016/j.cap.2024.11.008
Saiki Kitagawa , Toshihiro Nakamura
Epitaxial manganese-doped indium tin oxide (Mn-doped ITO) films with different Mn concentrations were deposited on single-crystal yttria-stabilized zirconia substrates using radio-frequency magnetron sputtering. The carrier concentration of the epitaxial Mn-doped ITO films could be controlled by changing the Mn doping concentration. The optical bandgaps of the films increased with the increase in the carrier concentration. Room-temperature ferromagnetism was observed in all films irrespective of the Mn concentration. The saturation magnetizations of the films increased with the increase in the carrier concentration, which suggests that delocalized charge carrier-mediated interaction model is one of the most probable mechanisms of the ferromagnetism in the Mn-doped ITO films. We found that the carrier concentration plays a crucial role in controlling optical and magnetic properties of the Mn-doped ITO films. The results of this study provide useful insight into the application of Mn-doped ITO films to ferromagnetic electrodes in spintronic devices.
利用射频磁控溅射技术在单晶钇稳定氧化锆基底上沉积了不同锰浓度的掺锰氧化铟锡（掺锰氧化铟锡）外延薄膜。外延掺锰 ITO 薄膜的载流子浓度可通过改变掺锰浓度来控制。薄膜的光带隙随着载流子浓度的增加而增大。无论锰的浓度如何，所有薄膜都具有室温铁磁性。薄膜的饱和磁化率随着载流子浓度的增加而增加，这表明电荷载流子介导的非局域相互作用模型是掺锰 ITO 薄膜铁磁性的最可能机制之一。我们发现，载流子浓度在控制掺锰 ITO 薄膜的光学和磁学特性方面起着至关重要的作用。这项研究的结果为将掺锰 ITO 薄膜应用于自旋电子器件中的铁磁电极提供了有益的启示。
{"title":"Carrier concentration dependence of optical and magnetic properties in epitaxial manganese-doped indium tin oxide films with different manganese concentrations","authors":"Saiki Kitagawa , Toshihiro Nakamura","doi":"10.1016/j.cap.2024.11.008","DOIUrl":"10.1016/j.cap.2024.11.008","url":null,"abstract":"<div><div>Epitaxial manganese-doped indium tin oxide (Mn-doped ITO) films with different Mn concentrations were deposited on single-crystal yttria-stabilized zirconia substrates using radio-frequency magnetron sputtering. The carrier concentration of the epitaxial Mn-doped ITO films could be controlled by changing the Mn doping concentration. The optical bandgaps of the films increased with the increase in the carrier concentration. Room-temperature ferromagnetism was observed in all films irrespective of the Mn concentration. The saturation magnetizations of the films increased with the increase in the carrier concentration, which suggests that delocalized charge carrier-mediated interaction model is one of the most probable mechanisms of the ferromagnetism in the Mn-doped ITO films. We found that the carrier concentration plays a crucial role in controlling optical and magnetic properties of the Mn-doped ITO films. The results of this study provide useful insight into the application of Mn-doped ITO films to ferromagnetic electrodes in spintronic devices.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 60-69"},"PeriodicalIF":2.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698211","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}
Pub Date : 2024-11-13DOI: 10.1016/j.cap.2024.11.005
Dongjin Jang , Minsik Kong , Jong Mok Ok
Many quantum materials undergo phase transitions above room temperature. However, thermodynamic evidence of these phase transitions is relatively scarce. For instance, detailed specific heat anomalies have rarely been reported for the transitions. In addition to considering intrinsic factors that obscure the thermodynamic manifestation of relevant degrees of freedom, it is also important to revisit measurement techniques based on firmly established physical principles. In this study, we introduce a transient heat-flux method for measuring heat capacity of solids, and report a specific heat anomaly in VO2, along with the reproduction of the standard specific heat capacity data of Cu. At present, our method is capable of measuring heat capacities ranging from 1 J/mol⋅K to 400 J/mol⋅K with an uncertainty of 5% across a temperature range from room temperature to 100 °C.
{"title":"Transient heat-flux method for measuring heat capacity: Examples from Cu and VO2","authors":"Dongjin Jang , Minsik Kong , Jong Mok Ok","doi":"10.1016/j.cap.2024.11.005","DOIUrl":"10.1016/j.cap.2024.11.005","url":null,"abstract":"<div><div>Many quantum materials undergo phase transitions above room temperature. However, thermodynamic evidence of these phase transitions is relatively scarce. For instance, detailed specific heat anomalies have rarely been reported for the transitions. In addition to considering intrinsic factors that obscure the thermodynamic manifestation of relevant degrees of freedom, it is also important to revisit measurement techniques based on firmly established physical principles. In this study, we introduce a transient heat-flux method for measuring heat capacity of solids, and report a specific heat anomaly in VO<sub>2</sub>, along with the reproduction of the standard specific heat capacity data of Cu. At present, our method is capable of measuring heat capacities ranging from 1 J/mol⋅K to 400 J/mol⋅K with an uncertainty of 5% across a temperature range from room temperature to 100 °C.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 55-59"},"PeriodicalIF":2.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662099","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}
Pub Date : 2024-11-13DOI: 10.1016/j.cap.2024.11.006
J. Jeon , H.J. Kim , B.S. Chun , S.J. Lee
This study investigates the resonant behavior of a nanostructured absorber consisting of a metal hole array (MHA) on a dielectric layer (BCB) forming a cavity on a metal ground plane (MGP). By varying the thickness of the BCB layer, the resonance spectra were analyzed under different conditions. Our simulations reveal the intricate interplay between surface plasmon and Fabry-Perot resonances within the MHA-BCB-MGP structure. We observe that as the dielectric thickness changes, the resonance peaks shift, exhibiting phenomena such as Rabi splitting and bifurcation. These features are particularly pronounced under transverse magnetic polarization, indicating the complex interaction between different resonance modes and polarization states. In addition, changes in MHA diameter affected the dominance of either surface plasmon or Fabry-Perot resonances, illustrating the complex relationship between structure and resonance behavior. Reflection spectra under different polarizations and angles of incidence showed agreement between simulation and experiment, validating the proposed model.
{"title":"Interplay of surface plasmon and Fabry-Perot resonances in metallic hole arrays on dielectric layers","authors":"J. Jeon , H.J. Kim , B.S. Chun , S.J. Lee","doi":"10.1016/j.cap.2024.11.006","DOIUrl":"10.1016/j.cap.2024.11.006","url":null,"abstract":"<div><div>This study investigates the resonant behavior of a nanostructured absorber consisting of a metal hole array (MHA) on a dielectric layer (BCB) forming a cavity on a metal ground plane (MGP). By varying the thickness of the BCB layer, the resonance spectra were analyzed under different conditions. Our simulations reveal the intricate interplay between surface plasmon and Fabry-Perot resonances within the MHA-BCB-MGP structure. We observe that as the dielectric thickness changes, the resonance peaks shift, exhibiting phenomena such as Rabi splitting and bifurcation. These features are particularly pronounced under transverse magnetic polarization, indicating the complex interaction between different resonance modes and polarization states. In addition, changes in MHA diameter affected the dominance of either surface plasmon or Fabry-Perot resonances, illustrating the complex relationship between structure and resonance behavior. Reflection spectra under different polarizations and angles of incidence showed agreement between simulation and experiment, validating the proposed model.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 81-87"},"PeriodicalIF":2.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142698213","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}
Pub Date : 2024-11-05DOI: 10.1016/j.cap.2024.10.016
Sang Woo Kim, Yeon Jun Choi, Ye Rae Kim, Deok Hyeon Kim, Ye Jin In, Tae Han Kim, Bo Wha Lee
In this study, we investigated how adding nanopowders to a micropowder affects the packing fraction and permeability. The micropowder used was a Fe-Ni crystalline alloy, which was sieved to less than 38 μm to minimize the effect of particle size distribution. The nanopowders, magnetic Ni and nonmagnetic Zn, were added to the Fe-Ni at weight ratios of 95:5, 90:10, 85:15, and 80:20. The results showed that the permeability of Fe-Ni was higher when sieved to 38 μm compared to the overall particle size. When the magnetic Ni nanopowder was added to the Fe-Ni powder sieved to 38 μm, both the packing fraction and permeability increased up to a ratio of 85:15 and then decreased. On the other hand, when the nonmagnetic Zn nanopowder was added, the packing fraction increased up to a ratio of 85:15 and then decreased, while the permeability continued to decrease.
{"title":"Permeability modulation of Fe-Ni/nanoparticle (Ni, Zn) soft magnetic composites","authors":"Sang Woo Kim, Yeon Jun Choi, Ye Rae Kim, Deok Hyeon Kim, Ye Jin In, Tae Han Kim, Bo Wha Lee","doi":"10.1016/j.cap.2024.10.016","DOIUrl":"10.1016/j.cap.2024.10.016","url":null,"abstract":"<div><div>In this study, we investigated how adding nanopowders to a micropowder affects the packing fraction and permeability. The micropowder used was a Fe-Ni crystalline alloy, which was sieved to less than 38 μm to minimize the effect of particle size distribution. The nanopowders, magnetic Ni and nonmagnetic Zn, were added to the Fe-Ni at weight ratios of 95:5, 90:10, 85:15, and 80:20. The results showed that the permeability of Fe-Ni was higher when sieved to 38 μm compared to the overall particle size. When the magnetic Ni nanopowder was added to the Fe-Ni powder sieved to 38 μm, both the packing fraction and permeability increased up to a ratio of 85:15 and then decreased. On the other hand, when the nonmagnetic Zn nanopowder was added, the packing fraction increased up to a ratio of 85:15 and then decreased, while the permeability continued to decrease.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 42-46"},"PeriodicalIF":2.4,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662100","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}
Pub Date : 2024-11-02DOI: 10.1016/j.cap.2024.10.017
Palvinder Singh , Amit Sachdeva , Parmod K. Singh , M.Z.A. Yahya , S.N.F. Yusuf , Markus Diantoro , Famiza Abdul Latif
The detail study of structural and ionic conductivity characterization of Poly (ethyl methacrylate) (PEMA) based polymer composite electrolyte were modified by the incorporation of Cadmium sulphide (CdS) nanomaterial. PEMA in addition with 40 % wt. potassium iodide (KI) and ethylene carbonate (EC) having 60 % wt., has the highest ionic conductivity of 4.65 × 10−5 S/cm when employed the solution casting technique. Cadmium Sulphide (CdS) was incorporated with PEMA + KI 40 % wt. + EC 60 % wt. sample to get maximum conductivity sample. The highest ionic conductivity 2.65×10−3S/cm, was attained at 7 % weight percentage of Cadmium sulphide (CdS). The conductive sample's morphology was examined using SEM, its amorphicity and crystalline structure was investigated using Fourier transform infrared (FTIR) technique, and FTIR 'wavenumbers of the maximum conductive sample of PEMA polymer + KI salt + EC plastizer and PEMA polymer + KI salt + EC plastizer + CdS nanoparticles were compared. X-ray diffraction (XRD) was used to identify the amorphous nature of the maximum conductive sample of polymer composite electrolyte. Differential scanning calorimetry (DSC) analysis was used to find out the glass transition (Tg) temperature of maximum conducting sample of polymer composite. The doctor blade method was employed to develop the dye sensitized solar cell (DSSC), and it had been observed that, under one sunlight situation, the energy conversion efficiency was 2.09 %, having parameters fill factor was 79.77 %.
{"title":"Effect of cadmium sulphide on poly (ethyl methacrylate) (PEMA) based electrolyte nanocomposite and its application in dye sensitized solar cell (DSSC)","authors":"Palvinder Singh , Amit Sachdeva , Parmod K. Singh , M.Z.A. Yahya , S.N.F. Yusuf , Markus Diantoro , Famiza Abdul Latif","doi":"10.1016/j.cap.2024.10.017","DOIUrl":"10.1016/j.cap.2024.10.017","url":null,"abstract":"<div><div>The detail study of structural and ionic conductivity characterization of Poly (ethyl methacrylate) (PEMA) based polymer composite electrolyte were modified by the incorporation of Cadmium sulphide (CdS) nanomaterial. PEMA in addition with 40 % wt. potassium iodide (KI) and ethylene carbonate (EC) having 60 % wt., has the highest ionic conductivity of 4.65 × 10<sup>−5</sup> S/cm when employed the solution casting technique. Cadmium Sulphide (CdS) was incorporated with PEMA + KI 40 % wt. + EC 60 % wt. sample to get maximum conductivity sample. The highest ionic conductivity 2.65×10<sup>−3</sup>S/cm, was attained at 7 % weight percentage of Cadmium sulphide (CdS). The conductive sample's morphology was examined using SEM, its amorphicity and crystalline structure was investigated using Fourier transform infrared (FTIR) technique, and FTIR 'wavenumbers of the maximum conductive sample of PEMA polymer + KI salt + EC plastizer and PEMA polymer + KI salt + EC plastizer + CdS nanoparticles were compared. X-ray diffraction (XRD) was used to identify the amorphous nature of the maximum conductive sample of polymer composite electrolyte. Differential scanning calorimetry (DSC) analysis was used to find out the glass transition (Tg) temperature of maximum conducting sample of polymer composite. The doctor blade method was employed to develop the dye sensitized solar cell (DSSC), and it had been observed that, under one sunlight situation, the energy conversion efficiency was 2.09 %, having parameters fill factor was 79.77 %.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 36-41"},"PeriodicalIF":2.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662101","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}
Pub Date : 2024-10-30DOI: 10.1016/j.cap.2024.10.014
Brahim Marfoua , Jisang Hong
Altermagnets represent a distinctive class of antiferromagnetic materials characterized by non-overlapping spin bands and attract extensive research efforts. Herein, we investigate the interplay among electronic, magnetic, and spin transport phenomena of the Janus V2SeTeO monolayer. The Janus monolayer has a direct band gap of 0.32 eV. The Janus V2SeTeO layer has an in-plane magnetic anisotropy along (110) direction. The incorporation of spin-orbit coupling (SOC) induces a Rashba-type band structure with a Rashba coefficient of 1.02 eV Å. The Rashba coefficient is insensitive to the compressive strain. In contrast, it is suppressed with tensile strain and becomes almost zero at 3 % tensile strain. The maximum SHC of around ∼ −65 (ℏ/e)S/cm is achieved with hole doping. The magnitudes of SHC remain comparable to those in typical topological materials. Overall, this investigation provides fundamental insights into the magnetic, Rashba, and spin transport properties of the Janus V2SeTeO altermagnet monolayer.
{"title":"Strain-dependent Rashba effect, and spin Hall conductivity in the altermagnetic Janus V2SeTeO monolayer","authors":"Brahim Marfoua , Jisang Hong","doi":"10.1016/j.cap.2024.10.014","DOIUrl":"10.1016/j.cap.2024.10.014","url":null,"abstract":"<div><div>Altermagnets represent a distinctive class of antiferromagnetic materials characterized by non-overlapping spin bands and attract extensive research efforts. Herein, we investigate the interplay among electronic, magnetic, and spin transport phenomena of the Janus V<sub>2</sub>SeTeO monolayer. The Janus monolayer has a direct band gap of 0.32 eV. The Janus V<sub>2</sub>SeTeO layer has an in-plane magnetic anisotropy along (110) direction. The incorporation of spin-orbit coupling (SOC) induces a Rashba-type band structure with a Rashba coefficient of 1.02 eV Å. The Rashba coefficient is insensitive to the compressive strain. In contrast, it is suppressed with tensile strain and becomes almost zero at 3 % tensile strain. The maximum SHC of around ∼ −65 (ℏ/e)S/cm is achieved with hole doping. The magnitudes of SHC remain comparable to those in typical topological materials. Overall, this investigation provides fundamental insights into the magnetic, Rashba, and spin transport properties of the Janus V<sub>2</sub>SeTeO altermagnet monolayer.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 47-54"},"PeriodicalIF":2.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662098","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}
Pub Date : 2024-10-30DOI: 10.1016/j.cap.2024.10.015
Jun-Hwan Choi, Jung-Sik Kim
Ultra-thin (20 μm) silicon strain gauges were fabricated with silicon-on-insulator (SOI) wafer by a newly-conceived wet etching process. Buffered oxide etchant (BOE, NH4F: HF = 6:1) solution with additives of octylamine and octanol was used for wet etching process in which the operating temperature was 50°C. Photoresist as a passivation layer was deposited on the upper side of SOI wafer to minimize strain gauge damage by chemical etchants. Small amount of octylamine and octanol were added to BOE solution to improve surface wettability and SiO2/Si selectivity. The fabricated strain gauges were attached to the pressure diaphragm and the performance of strain gauge was investigated by measuring with the hydraulic pressure system. The resistance changed linearly with tensile and compressive strains. Maximum values of non-linearity, hysteresis, thermal coefficient of resistance (TCR) and sensitivity were -0.341 %, 0.909 %, 4128 ppm/°C and 34.22 mV/V respectively. The fabricated strain gauges might be well applicable to the hydrogen pressure sensor which is detectable for high pressure range (0–900 bar).
{"title":"Design and fabrication of ultrathin silicon-based strain gauges for piezoresistive pressure sensor","authors":"Jun-Hwan Choi, Jung-Sik Kim","doi":"10.1016/j.cap.2024.10.015","DOIUrl":"10.1016/j.cap.2024.10.015","url":null,"abstract":"<div><div>Ultra-thin (20 μm) silicon strain gauges were fabricated with silicon-on-insulator (SOI) wafer <strong>by a newly-conceived wet etching process. Buffered oxide etchant (BOE, NH</strong><sub><strong>4</strong></sub><strong>F: HF = 6:1) solution with additives of octylamine and octanol was used for wet etching process in which the operating temperature was 50°C.</strong> Photoresist as a passivation layer was deposited on the upper side of SOI wafer to minimize strain gauge damage by chemical etchants. Small amount of octylamine and octanol were added to BOE solution to improve surface wettability and SiO<sub>2</sub>/Si selectivity. The fabricated strain gauges were attached to the pressure diaphragm and the performance of strain gauge was investigated by measuring with the hydraulic pressure system. The resistance changed linearly with tensile and compressive strains. <strong>Maximum values of non-linearity, hysteresis, thermal coefficient of resistance (TCR) and sensitivity were -0.341 %, 0.909 %, 4128 ppm/°C and 34.22 mV/V respectively. The fabricated strain gauges might be well applicable to the hydrogen pressure sensor which is detectable for high pressure range (0–900 bar).</strong></div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"69 ","pages":"Pages 28-35"},"PeriodicalIF":2.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573268","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}
Pub Date : 2024-10-24DOI: 10.1016/j.cap.2024.10.007
Hyun Don Kim , Minseon Gu , Kyu-Myung Lee , Hanyeol Ahn , Jinwoo Byun , Gukhyon Yon , Junghyun Beak , Hyeongjoon Lim , Jaemo Jung , Jaehyeon Park , Jwa Soon Kim , HaeJoon Hahm , Soobang Kim , Won Ja Min , Moon Seop Hyun , Yun Chang Park , Gyungtae Kim , Yongsup Park , Moonsup Han , Eunjip Choi , Young Jun Chang
Silicon nitride (SiNx) serves as the charge trap layer in current 3D NAND flash memory devices. The precise formation mechanism and electronic structure of localized defect trap states in SiNx remain elusive. Here, we present a refined experimental methodology to elucidate the in-gap defect states and the band gaps in amorphous SiNx thin films. Our approach integrates high-resolution reflection electron energy loss spectroscopy (REELS) and spectroscopic ellipsometry (SE) for comprehensive analysis. By systematical analysis, we aim to provide a robust method for determining in-gap electronic states in SiNx. We investigated two different SiNx films prepared by plasma-enhanced chemical vapor deposition and sputtering. Our analysis revealed several distinct in-gap states and determined band gap energies. This approach not only provide advanced spectroscopic methods to characterize the defect electronic states in SiNx, but also applicable to other large band gap semiconductors or dielectrics to predict device-level characteristics for future devices.
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