To investigate the Ta5+-substitution effects on crystal structure and ferroelectric property in HfO2-based films, TaxHf1−xO2+δ films with various film thicknesses and Ta content were prepared. The ferroelectric orthorhombic phase was formed in a wide film thickness range of 20–100 nm while in a narrow composition range of x = 0.10–0.14. These thickness-insensitive and composition-sensitive characteristics of Ta5+-substituted HfO2 film are similar to Y3+ rather than Zr4+. The X-ray photoelectron spectroscopy measurement suggests that the ionic state of Ta is not reduced and TaxHf1−xO2+δ film has an excess oxygen state. The excess oxygen may consist of a combination of oxygen vacancies and more interstitial oxygens. These defects facilitate the formation of the ferroelectric phasebut also decrease the breakdown voltage and increase the leakage current in Ta5+-substituted HfO2 films. On the other hand, the generation of excess oxygen indicates the possibility of controlling oxygen vacancies which deteriorate fatigue and retention properties.
{"title":"Ta5+-substitution effects on crystal structure and ferroelectric property in HfO2-based films","authors":"Yoshiki Maekawa, Takanori Mimura, Yoshiyuki Inaguma, Hiroshi Uchida, Yuxian Hu, Kazuki Okamoto and Hiroshi Funakubo","doi":"10.35848/1347-4065/ad6fa9","DOIUrl":"https://doi.org/10.35848/1347-4065/ad6fa9","url":null,"abstract":"To investigate the Ta5+-substitution effects on crystal structure and ferroelectric property in HfO2-based films, TaxHf1−xO2+δ films with various film thicknesses and Ta content were prepared. The ferroelectric orthorhombic phase was formed in a wide film thickness range of 20–100 nm while in a narrow composition range of x = 0.10–0.14. These thickness-insensitive and composition-sensitive characteristics of Ta5+-substituted HfO2 film are similar to Y3+ rather than Zr4+. The X-ray photoelectron spectroscopy measurement suggests that the ionic state of Ta is not reduced and TaxHf1−xO2+δ film has an excess oxygen state. The excess oxygen may consist of a combination of oxygen vacancies and more interstitial oxygens. These defects facilitate the formation of the ferroelectric phasebut also decrease the breakdown voltage and increase the leakage current in Ta5+-substituted HfO2 films. On the other hand, the generation of excess oxygen indicates the possibility of controlling oxygen vacancies which deteriorate fatigue and retention properties.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"9 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247984","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 : 2024-09-16DOI: 10.35848/1347-4065/ad7790
Kohei Yamamoto, Yuji Yoshida and Takurou N. Murakami
Surface treatment of SnO2 as an electron transport layer is essential for improving charge transport and device performance in the fabrication of perovskite solar cells. In this study, oxygen plasma with a controlled ion–radical composition ratio was used for rapid surface treatment to clean the surface of SnO2, and its performance was compared with that of the conventional UV–ozone treatment. Consequently, the plasma treatment succeeded in increasing the processing speed up to 40 times faster than that required for the conventional UV–ozone pretreatment. Furthermore, plasma pretreatment improved the photostability of solar cells.
{"title":"Rapid oxygen plasma treatment of tin oxide layers for improving the light stability of perovskite solar cells","authors":"Kohei Yamamoto, Yuji Yoshida and Takurou N. Murakami","doi":"10.35848/1347-4065/ad7790","DOIUrl":"https://doi.org/10.35848/1347-4065/ad7790","url":null,"abstract":"Surface treatment of SnO2 as an electron transport layer is essential for improving charge transport and device performance in the fabrication of perovskite solar cells. In this study, oxygen plasma with a controlled ion–radical composition ratio was used for rapid surface treatment to clean the surface of SnO2, and its performance was compared with that of the conventional UV–ozone treatment. Consequently, the plasma treatment succeeded in increasing the processing speed up to 40 times faster than that required for the conventional UV–ozone pretreatment. Furthermore, plasma pretreatment improved the photostability of solar cells.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"16 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247987","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 : 2024-09-12DOI: 10.35848/1347-4065/ad7146
Hiromi Osaka, Takaaki Morimoto and Keisuke Ishii
The rolling-extended orientation technique and plate-like NaNbO3 (NN) single crystal particles prepared by a single-step molten salt synthesis, both of which have been developed to fabricate (K, Na)NbO3 (KNN) textured ceramics, were utilized to control the growth orientation of KNN single crystals synthesized by a rapid solid-stated crystal growth (RSSCG) method. As the seed crystals, two kinds of NN single crystal particles were synthesized using pure NaCl and KCl-NaCl mixed molten salts. Plate-like KNN single crystals of about 1 cm squares with the upper and lower faces almost parallel to the (100) (001) planes were obtained with a probability exceeding 50% when NN single crystal particles were synthesized from mixed salts and were subsequently thermal-treated again in Na2CO3-NaCl mixed molten salts under appropriate conditions to remove the Bi element, which is known as the suppression factor of the crystal growth. The average crystal growth rate was 0.6–1.2 mm h−1. Controlling the growth orientation of KNN single crystals produced by the SSCG method using seed crystals other than KTaO3 single crystals was successfully accomplished for the first time.
滚动扩展取向技术和单步熔盐合成法制备的板状 NaNbO3（NNN）单晶颗粒都是为制造（K，Na）NbO3（KNN）质地陶瓷而开发的，我们利用这两种技术来控制快速固态晶体生长（RSSCG）法合成的 KNN 单晶的生长取向。以纯 NaCl 和 KCl-NaCl 混合熔盐作为籽晶，合成了两种 NN 单晶颗粒。用混合盐合成 NNN 单晶颗粒，然后在 Na2CO3-NaCl 混合熔盐中以适当条件再次进行热处理以去除被称为晶体生长抑制因子的 Bi 元素，可获得上下面几乎平行于（100）（001）平面的约 1 厘米见方的板状 KNN 单晶，概率超过 50%。晶体平均生长速度为 0.6-1.2 mm h-1。利用 KTaO3 单晶以外的籽晶控制 SSCG 法制备的 KNN 单晶的生长取向首次获得成功。
{"title":"Growth orientation control in rapid solid-state crystal growth of (K,Na)NbO3 single crystals using plate-like NaNbO3 single crystal particles","authors":"Hiromi Osaka, Takaaki Morimoto and Keisuke Ishii","doi":"10.35848/1347-4065/ad7146","DOIUrl":"https://doi.org/10.35848/1347-4065/ad7146","url":null,"abstract":"The rolling-extended orientation technique and plate-like NaNbO3 (NN) single crystal particles prepared by a single-step molten salt synthesis, both of which have been developed to fabricate (K, Na)NbO3 (KNN) textured ceramics, were utilized to control the growth orientation of KNN single crystals synthesized by a rapid solid-stated crystal growth (RSSCG) method. As the seed crystals, two kinds of NN single crystal particles were synthesized using pure NaCl and KCl-NaCl mixed molten salts. Plate-like KNN single crystals of about 1 cm squares with the upper and lower faces almost parallel to the (100) (001) planes were obtained with a probability exceeding 50% when NN single crystal particles were synthesized from mixed salts and were subsequently thermal-treated again in Na2CO3-NaCl mixed molten salts under appropriate conditions to remove the Bi element, which is known as the suppression factor of the crystal growth. The average crystal growth rate was 0.6–1.2 mm h−1. Controlling the growth orientation of KNN single crystals produced by the SSCG method using seed crystals other than KTaO3 single crystals was successfully accomplished for the first time.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"9 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247991","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 : 2024-09-12DOI: 10.35848/1347-4065/ad7147
Namık Kemal Gözüaçık and Sedat Alkoy
This study focused on analyzing the ferroelectric, piezoelectric, and dielectric properties of lead-free Bi0.487Na0.427K0.06Ba0.026TiO3 (0.854BNT-0.12BKT-0.026BT) ternary ceramic system by systematically doping 0.001, 0.01, 0.1, 0.5, and 1.0 mol% Gd2O3. The specific composition that was investigated is located at the tetragonal side of the rhombohedral-tetragonal morphotropic phase boundary (MPB) region. Undoped and Gd-doped BNT-BKT-BT ceramics were produced by the conventional solid-state reaction method. Ferroelectric, piezoelectric, and dielectric properties of ceramics were analyzed by carrying out electrical measurements from sintered samples. An ultrahigh field-induced unipolar strain of 0.52% at 65 kV cm−1, with a converse piezoelectric coefficient d33* of up to 795 pm V−1, was achieved with 0.5 mol% Gd doping. This was attributed to the Gd dopant disrupting the normal ferroelectric order and leading to the formation of a nonpolar relaxor phase. The field-induced transition from the nonpolar relaxor phase to the normal ferroelectric phase resulted in relatively large field-induced strain values in the 0.5 mol% Gd-doped ceramics. These results suggest that Gd-doped BNT-BKT-BT ceramics hold promise for digital actuator applications.
{"title":"Origin of the ultrahigh field-induced strain in the Gd-doped 0.854Bi0.5Na0.5TiO3-0.12Bi0.5K0.5TiO3-0.026BaTiO3 ternary ceramic system","authors":"Namık Kemal Gözüaçık and Sedat Alkoy","doi":"10.35848/1347-4065/ad7147","DOIUrl":"https://doi.org/10.35848/1347-4065/ad7147","url":null,"abstract":"This study focused on analyzing the ferroelectric, piezoelectric, and dielectric properties of lead-free Bi0.487Na0.427K0.06Ba0.026TiO3 (0.854BNT-0.12BKT-0.026BT) ternary ceramic system by systematically doping 0.001, 0.01, 0.1, 0.5, and 1.0 mol% Gd2O3. The specific composition that was investigated is located at the tetragonal side of the rhombohedral-tetragonal morphotropic phase boundary (MPB) region. Undoped and Gd-doped BNT-BKT-BT ceramics were produced by the conventional solid-state reaction method. Ferroelectric, piezoelectric, and dielectric properties of ceramics were analyzed by carrying out electrical measurements from sintered samples. An ultrahigh field-induced unipolar strain of 0.52% at 65 kV cm−1, with a converse piezoelectric coefficient d33* of up to 795 pm V−1, was achieved with 0.5 mol% Gd doping. This was attributed to the Gd dopant disrupting the normal ferroelectric order and leading to the formation of a nonpolar relaxor phase. The field-induced transition from the nonpolar relaxor phase to the normal ferroelectric phase resulted in relatively large field-induced strain values in the 0.5 mol% Gd-doped ceramics. These results suggest that Gd-doped BNT-BKT-BT ceramics hold promise for digital actuator applications.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"197 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247990","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 : 2024-09-12DOI: 10.35848/1347-4065/ad70c1
Sou Yasuhara, Akira Orio, Shintaro Yasui and Takuya Hoshina
BaTiO3, known for its exceptional ferroelectric properties, is extensively applied in multi-layer ceramics capacitors (MLCCs). Achieving reliable, high-performance MLCCs requires sophisticated ceramics processes, notably in synthesizing submicron-order BaTiO3 powder with a narrow size distribution. Among various synthesis methods explored for submicron-size BaTiO3 powder, room temperature liquid-phase synthesis is most desirable due to its cost-effectiveness and large batch availability. In this study, we propose a synthesis method for obtaining BaTiO3 nanopowder at room temperature using titanium bis(ammonium lactato) dihydroxide and Ba(OH)2·8H2O as starting materials, reacted in tert-butylamine with NaOH and ethanol. The resulting powder, exhibiting a cubic phase of BaTiO3 with an average particle size of 35.8 nm, was obtained after a 7-day reaction at room temperature. Characterization involved X-ray diffraction, differential thermal analysis‒thermogravimetry, and scanning electron microscopy. Subsequently, the powder was used to sinter a BaTiO3 ceramic, whose dielectric performance was then evaluated.
{"title":"Room temperature synthesis of BaTiO3 nanoparticles using titanium bis(ammonium lactato) dihydroxide","authors":"Sou Yasuhara, Akira Orio, Shintaro Yasui and Takuya Hoshina","doi":"10.35848/1347-4065/ad70c1","DOIUrl":"https://doi.org/10.35848/1347-4065/ad70c1","url":null,"abstract":"BaTiO3, known for its exceptional ferroelectric properties, is extensively applied in multi-layer ceramics capacitors (MLCCs). Achieving reliable, high-performance MLCCs requires sophisticated ceramics processes, notably in synthesizing submicron-order BaTiO3 powder with a narrow size distribution. Among various synthesis methods explored for submicron-size BaTiO3 powder, room temperature liquid-phase synthesis is most desirable due to its cost-effectiveness and large batch availability. In this study, we propose a synthesis method for obtaining BaTiO3 nanopowder at room temperature using titanium bis(ammonium lactato) dihydroxide and Ba(OH)2·8H2O as starting materials, reacted in tert-butylamine with NaOH and ethanol. The resulting powder, exhibiting a cubic phase of BaTiO3 with an average particle size of 35.8 nm, was obtained after a 7-day reaction at room temperature. Characterization involved X-ray diffraction, differential thermal analysis‒thermogravimetry, and scanning electron microscopy. Subsequently, the powder was used to sinter a BaTiO3 ceramic, whose dielectric performance was then evaluated.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"110 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218093","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 : 2024-09-12DOI: 10.35848/1347-4065/ad6e93
Kenji Ohwada and Akihiko Machida
X-ray diffraction topography was used to observe two distinct ferroelectric domains in BaTiO3. The use of highly-parallel X-rays and a high-resolution detector with approximately 200 nm resolution enabled us to successfully characterize two distinct domains, each with sizes of the order of 10 μm. Along with the local rocking curve of the bulk crystal, we generated width maps corresponding to crystal properties including defects and, strain. This information is beneficial for understanding domain behavior, and the measurement system can be expected to become a powerful tool for in situ measurements of processes requiring domain control.
我们利用 X 射线衍射拓扑图观察了 BaTiO3 中两个不同的铁电畴。利用高度平行的 X 射线和分辨率约为 200 nm 的高分辨率探测器，我们成功地确定了两个不同畴的特征，每个畴的大小约为 10 μm。我们生成了与晶体属性（包括缺陷和应变）相对应的宽度图，以及块状晶体的局部摇摆曲线。这些信息有助于了解畴的行为，该测量系统有望成为现场测量需要畴控制的过程的有力工具。
{"title":"Observation of ferroelectric domains in BaTiO3 by synchrotron radiation X-ray diffraction topography","authors":"Kenji Ohwada and Akihiko Machida","doi":"10.35848/1347-4065/ad6e93","DOIUrl":"https://doi.org/10.35848/1347-4065/ad6e93","url":null,"abstract":"X-ray diffraction topography was used to observe two distinct ferroelectric domains in BaTiO3. The use of highly-parallel X-rays and a high-resolution detector with approximately 200 nm resolution enabled us to successfully characterize two distinct domains, each with sizes of the order of 10 μm. Along with the local rocking curve of the bulk crystal, we generated width maps corresponding to crystal properties including defects and, strain. This information is beneficial for understanding domain behavior, and the measurement system can be expected to become a powerful tool for in situ measurements of processes requiring domain control.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"56 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142247989","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}
NaNbO3, AgNbO3, and KNbO3 with ABO3-type perovskite systems are known to possess good ferroelectric properties. In their traditional average structure, a change in the A-site ion size changes the involved tolerance factor. Herein, we directly determined the rattling space of each atom through local structure analysis. By combining a pair distribution function and an extended X-ray absorption fine structure, this analysis revealed that the bonding sites with large fluctuations varied with varying ion sizes. Experimental evidence including soft X-ray absorption spectroscopy, indicates that the A-site ions are hybridized with oxygen.
众所周知，具有 ABO3 型包晶体系的 NaNbO3、AgNbO3 和 KNbO3 具有良好的铁电特性。在它们的传统平均结构中，A-位离子尺寸的变化会改变相关的容限因子。在这里，我们通过局部结构分析直接确定了每个原子的响度空间。通过结合原子对分布函数和扩展 X 射线吸收精细结构，该分析揭示了具有较大波动的成键位点随离子尺寸的变化而变化。包括软 X 射线吸收光谱在内的实验证据表明，A 位离子与氧杂化。
{"title":"Local and electronic structures of NaNbO3, AgNbO3, and KNbO3","authors":"Yasuhiro Yoneda, Tohru Kobayashi, Takuya Tsuji, Daiju Matsumura, Yuji Saitoh and Yuji Noguchi","doi":"10.35848/1347-4065/ad72fc","DOIUrl":"https://doi.org/10.35848/1347-4065/ad72fc","url":null,"abstract":"NaNbO3, AgNbO3, and KNbO3 with ABO3-type perovskite systems are known to possess good ferroelectric properties. In their traditional average structure, a change in the A-site ion size changes the involved tolerance factor. Herein, we directly determined the rattling space of each atom through local structure analysis. By combining a pair distribution function and an extended X-ray absorption fine structure, this analysis revealed that the bonding sites with large fluctuations varied with varying ion sizes. Experimental evidence including soft X-ray absorption spectroscopy, indicates that the A-site ions are hybridized with oxygen.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"3 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142248038","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 : 2024-09-11DOI: 10.35848/1347-4065/ad7343
Akihiko Teshigahara, Tetsuya Enomoto, Hideo Yamada and Shinya Yoshida
Scandium-doped aluminum nitride thin films are key materials for MEMS applications including bulk acoustic wave devices for communication. Although one drawback is the increase in the loss tangent with increasing Sc concentration, the loss tangent is reported to decrease after post-deposition annealing. However, the underlying mechanisms remain unclear. In this study, we propose the hypothesis that a low-resistivity thin layer near the surface of a substrate is one of the main reasons for the high loss tangent, and that annealing enhances the resistivity, eventually decreasing the loss tangent. The reasonability of the hypothesis was successfully confirmed by analyzing the frequency response of the loss tangent using an equivalent circuit with current–voltage characteristics, cathodoluminescence, etc. This achievement represents a significant step toward advanced methods for reducing the loss tangent and its application to other thin-film materials.
{"title":"Reduction mechanism of loss tangent of scandium-doped aluminum nitride thin film by post-deposition annealing","authors":"Akihiko Teshigahara, Tetsuya Enomoto, Hideo Yamada and Shinya Yoshida","doi":"10.35848/1347-4065/ad7343","DOIUrl":"https://doi.org/10.35848/1347-4065/ad7343","url":null,"abstract":"Scandium-doped aluminum nitride thin films are key materials for MEMS applications including bulk acoustic wave devices for communication. Although one drawback is the increase in the loss tangent with increasing Sc concentration, the loss tangent is reported to decrease after post-deposition annealing. However, the underlying mechanisms remain unclear. In this study, we propose the hypothesis that a low-resistivity thin layer near the surface of a substrate is one of the main reasons for the high loss tangent, and that annealing enhances the resistivity, eventually decreasing the loss tangent. The reasonability of the hypothesis was successfully confirmed by analyzing the frequency response of the loss tangent using an equivalent circuit with current–voltage characteristics, cathodoluminescence, etc. This achievement represents a significant step toward advanced methods for reducing the loss tangent and its application to other thin-film materials.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"12 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218100","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 : 2024-09-11DOI: 10.35848/1347-4065/ad760b
Kiranjot, Raymond Fan, R. O. M. Aboljadayel, David M. Burn, Kalel Alsaeed, Aidan T. Hindmarch and Paul Steadman
The soft X-ray reflectivity technique is frequently utilized for studying magnetization reversal in thin films due to its elemental and depth sensitivity. The characteristic hysteresis loops measured with this technique are dependent on both the magnetization direction in magnetic materials and the incident soft X-ray polarization. In this note, we have discussed these magneto-optical effects in soft X-ray reflectivity measurements. These effects can be exploited to probe magnetization reversal mechanisms driven by stimuli beyond conventional means of magnetic field. To demonstrate this, we have presented our investigations on current-induced magnetization switching in ferromagnet (FM)/heavy metal(HM) heterostructures.
软 X 射线反射率技术因其对元素和深度的敏感性，经常被用于研究薄膜中的磁化反转。使用该技术测量的特征磁滞回线取决于磁性材料的磁化方向和入射软 X 射线的偏振。在本说明中，我们讨论了软 X 射线反射率测量中的这些磁光效应。这些效应可用于探测由传统磁场刺激手段以外的刺激所驱动的磁化反转机制。为了证明这一点，我们介绍了对铁磁体（FM）/重金属（HM）异质结构中电流诱导磁化切换的研究。
{"title":"Using magneto-optical effects in soft X-ray reflectivity to study current driven magnetization reversal","authors":"Kiranjot, Raymond Fan, R. O. M. Aboljadayel, David M. Burn, Kalel Alsaeed, Aidan T. Hindmarch and Paul Steadman","doi":"10.35848/1347-4065/ad760b","DOIUrl":"https://doi.org/10.35848/1347-4065/ad760b","url":null,"abstract":"The soft X-ray reflectivity technique is frequently utilized for studying magnetization reversal in thin films due to its elemental and depth sensitivity. The characteristic hysteresis loops measured with this technique are dependent on both the magnetization direction in magnetic materials and the incident soft X-ray polarization. In this note, we have discussed these magneto-optical effects in soft X-ray reflectivity measurements. These effects can be exploited to probe magnetization reversal mechanisms driven by stimuli beyond conventional means of magnetic field. To demonstrate this, we have presented our investigations on current-induced magnetization switching in ferromagnet (FM)/heavy metal(HM) heterostructures.","PeriodicalId":14741,"journal":{"name":"Japanese Journal of Applied Physics","volume":"36 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218108","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 : 2024-09-11DOI: 10.35848/1347-4065/ad7342
Yoshinari Kimura, Michihiro Sasaki and Hironori Tohmyoh
Sensors for detecting chloride ions have been required for routine monitoring of industry and human health. This study proposes a concept of an ion sensor based on CuOx nanofilms with different oxygen contents. The CuOx-based sensors exhibited an increase in DC current for those with low oxygen content and a decrease for those with high oxygen content following exposure to a chloride ion solution. AC impedance analysis suggested differential reactions of chloride ions in the bulk and surface regions of CuOx, dependent on the oxygen content. For the CuOx-based sensors with a ratio of 0.78 oxygen to copper atoms at chloride ion concentrations of 10−1000 ppm, the sensitivity in the bulk region calculated from AC impedance was 61−2926, which was higher than the sensitivity of 1.3−2.6 calculated from DC impedance. Finally, CuOx-based sensors demonstrated identifiability for chloride ions compared to sodium and calcium ions.
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