With the development of thin film technology, particularly the increasing demand for research on group III nitride materials, the need for N ions has significantly increased. A wider and more efficient RF nitrogen atom source specifically designed for nitride film growth has been developed. To evaluate the nitrogen atom density from the RF nitrogen source, a global model of RF nitrogen gas discharge plasma was created. This model was calibrated by measuring the emission spectrum of RF nitrogen gas discharge, and the relationships between nitrogen atom density and actual working pressure, power, and discharge chamber size were determined. It was found that the nitrogen atom density increases with increasing power and initially increases with pressure before decreasing. Finally, the nitrogen atom density was determined, achieving an 18 % nitrogen atom dissociation rate and a nitrogen atom density of 5 × 1012/cm³ at an RF power of 400 W. This density is significantly higher than that of nitrogen ions, indicating that this is a nitrogen atom source with high purity.
随着薄膜技术的发展,特别是对 III 族氮化物材料研究的需求不断增加,对氮离子的需求也大大增加。专门为氮化物薄膜生长设计的更广泛、更高效的射频氮原子源已经开发出来。为了评估射频氮源的氮原子密度,创建了一个射频氮气放电等离子体的全局模型。通过测量射频氮气放电的发射光谱对该模型进行了校准,并确定了氮原子密度与实际工作压力、功率和放电室尺寸之间的关系。结果发现,氮原子密度随功率的增加而增加,最初随压力的增加而增加,然后再减小。最后,对氮原子密度进行了测定,在射频功率为 400 W 时,氮原子解离率为 18%,氮原子密度为 5 × 1012/cm³,明显高于氮离子的密度,表明这是一种高纯度的氮原子源。
{"title":"Development and diagnostic study of the RF nitrogen atom source","authors":"Mengting Li, Xin Xu, Wubin Wu, Shixiang Peng, Weiping Chen, Zhiyi Zhai, Qing Luo, Haiping Peng, Ailin Zhang","doi":"10.1016/j.vacuum.2024.113820","DOIUrl":"10.1016/j.vacuum.2024.113820","url":null,"abstract":"<div><div>With the development of thin film technology, particularly the increasing demand for research on group III nitride materials, the need for N ions has significantly increased. A wider and more efficient RF nitrogen atom source specifically designed for nitride film growth has been developed. To evaluate the nitrogen atom density from the RF nitrogen source, a global model of RF nitrogen gas discharge plasma was created. This model was calibrated by measuring the emission spectrum of RF nitrogen gas discharge, and the relationships between nitrogen atom density and actual working pressure, power, and discharge chamber size were determined. It was found that the nitrogen atom density increases with increasing power and initially increases with pressure before decreasing. Finally, the nitrogen atom density was determined, achieving an 18 % nitrogen atom dissociation rate and a nitrogen atom density of 5 × 10<sup>12</sup>/cm³ at an RF power of 400 W. This density is significantly higher than that of nitrogen ions, indicating that this is a nitrogen atom source with high purity.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113820"},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.vacuum.2024.113827
I.V. Malikov
Optimal conditions for obtaining high quality epitaxial Nb thin films on the monocrystalline sapphire R-plane by pulsed laser deposition in ultrahigh vacuum have been determined. The ratio of room temperature resistance to the residual resistance (RRR) on the substrate temperature has the maximum at about 630 °C. The RRR dependence on the growth rate has the maximum at growth rates of 3–6 nm/min. In epitaxial Nb films, there is a simultaneous increase in the value of RRR and growth misorientation of Nb(001) relatively sapphire R-plane. At the maximum value of RRR, the shapes of Nb X-ray diffraction (XRD) peaks (002) and (011) are symmetrical and close to the Gaussian distribution; at lower RRR values, the shapes of XRD peaks become asymmetrical and cannot be approximated by a single Gaussian distribution, and their shape can be described by the sum of several Gaussian functions. For all obtained films, full width at half maximum (FWHM) of Nb (002) and Nb (011) peaks are 0.2o and 0.4о, respectively. FWHM of Nb (002) rocking curves is 0.4o.
确定了在超高真空中通过脉冲激光沉积在单晶蓝宝石 R 平面上获得高质量铌外延薄膜的最佳条件。室温电阻与残余电阻 (RRR) 与基底温度的比率在约 630 °C 时达到最大值。RRR 与生长速率的关系在生长速率为 3-6 nm/min 时达到最大值。在外延铌薄膜中,RRR 值和相对蓝宝石 R 面的铌(001)生长错向同时增加。在 RRR 最大值时,铌 X 射线衍射(XRD)峰 (002) 和 (011) 的形状是对称的,接近高斯分布;在 RRR 值较低时,XRD 峰的形状变得不对称,不能用单一的高斯分布来近似,其形状可以用多个高斯函数的和来描述。对于所有获得的薄膜,铌(002)和铌(011)峰的半最大全宽(FWHM)分别为 0.2o 和 0.4о。铌(002)摇摆曲线的全宽最大值为 0.4o。
{"title":"Influence of the growth rate during Nb film pulsed laser deposition on the sapphire R-plane","authors":"I.V. Malikov","doi":"10.1016/j.vacuum.2024.113827","DOIUrl":"10.1016/j.vacuum.2024.113827","url":null,"abstract":"<div><div>Optimal conditions for obtaining high quality epitaxial Nb thin films on the monocrystalline sapphire R-plane by pulsed laser deposition in ultrahigh vacuum have been determined. The ratio of room temperature resistance to the residual resistance (RRR) on the substrate temperature has the maximum at about 630 °C. The RRR dependence on the growth rate has the maximum at growth rates of 3–6 nm/min. In epitaxial Nb films, there is a simultaneous increase in the value of RRR and growth misorientation of Nb(001) relatively sapphire R-plane. At the maximum value of RRR, the shapes of Nb X-ray diffraction (XRD) peaks (002) and (011) are symmetrical and close to the Gaussian distribution; at lower RRR values, the shapes of XRD peaks become asymmetrical and cannot be approximated by a single Gaussian distribution, and their shape can be described by the sum of several Gaussian functions. For all obtained films, full width at half maximum (FWHM) of Nb (002) and Nb (011) peaks are 0.2<sup>o</sup> and 0.4<sup>о</sup>, respectively. FWHM of Nb (002) rocking curves is 0.4<sup>o</sup>.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113827"},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.vacuum.2024.113823
Ziluo Cheng , Xiao Wang , Xiaona Li , Zhumin Li , Yinglin Hu , Qiao Jiang , Renwei Liu , Yuandi Hou , Min Li , Rui Zheng , Chuang Dong
High-temperature (HT) apparatus suffer from galling and seizure of contact interface, for which a wear-resistant film is helpful but challenging to design. In this work, the Cu-Ni-Al films prepared by magnetron sputtering provide effective wear-resistant protection for Ni-based superalloy over room temperature (RT) to 800 °C, decreasing the coefficient of friction by 45 %, 30 %, 15 % and wear rate by 97 %, 65 %, 62 % at RT, 400 °C, 600 °C, respectively, and exhibiting especially low wear rate 1.88 × 10−5mm3N−1m−1 at 800 °C. Layered structure with multiple oxidation states formed during friction is the crucial, with the Cu2O-rich layer and the CuO layer serving lubrication at RT and HT, respectively. The FCC + L12 structure ensures the high-temperature carrying capacity and film-substrate adhesion. AFM investigation exhibits the microscale tribological behavior is relevance with Ni + Al content. This work provides a novel strategy for the design and preparation of wide-temperature-range wear-resistant film.
高温(HT)设备的接触界面会出现咬合和咬合现象,为此需要设计一种耐磨薄膜,但这种薄膜的设计具有挑战性。在这项工作中,通过磁控溅射制备的铜-镍-铝薄膜为镍基超合金提供了有效的耐磨保护,在室温(RT)至 800 °C 的条件下,摩擦系数分别降低了 45%、30%、15%,磨损率在室温、400 °C 和 600 °C 条件下分别降低了 97%、65%、62%,尤其是在 800 °C 条件下,磨损率低至 1.88 × 10-5mm3N-1m-1。摩擦过程中形成的多氧化态分层结构是关键所在,其中富含 Cu2O 的层和 CuO 层分别在 RT 和 HT 条件下起到润滑作用。FCC + L12 结构确保了高温承载能力和薄膜与基底的粘附性。原子力显微镜研究表明,微尺度摩擦学行为与 Ni + Al 含量相关。这项研究为设计和制备宽温范围耐磨薄膜提供了一种新策略。
{"title":"Wide-temperature-range tribological properties of Cu-Ni-Al films with multiple oxidation states","authors":"Ziluo Cheng , Xiao Wang , Xiaona Li , Zhumin Li , Yinglin Hu , Qiao Jiang , Renwei Liu , Yuandi Hou , Min Li , Rui Zheng , Chuang Dong","doi":"10.1016/j.vacuum.2024.113823","DOIUrl":"10.1016/j.vacuum.2024.113823","url":null,"abstract":"<div><div>High-temperature (HT) apparatus suffer from galling and seizure of contact interface, for which a wear-resistant film is helpful but challenging to design. In this work, the Cu-Ni-Al films prepared by magnetron sputtering provide effective wear-resistant protection for Ni-based superalloy over room temperature (RT) to 800 °C, decreasing the coefficient of friction by 45 %, 30 %, 15 % and wear rate by 97 %, 65 %, 62 % at RT, 400 °C, 600 °C, respectively, and exhibiting especially low wear rate 1.88 × 10<sup>−5</sup>mm<sup>3</sup>N<sup>−1</sup>m<sup>−1</sup> at 800 °C. Layered structure with multiple oxidation states formed during friction is the crucial, with the Cu<sub>2</sub>O-rich layer and the CuO layer serving lubrication at RT and HT, respectively. The FCC + L1<sub>2</sub> structure ensures the high-temperature carrying capacity and film-substrate adhesion. AFM investigation exhibits the microscale tribological behavior is relevance with Ni + Al content. This work provides a novel strategy for the design and preparation of wide-temperature-range wear-resistant film.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113823"},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.vacuum.2024.113824
Radek Holeňák , Dmitrii Moldarev , Eleni Ntemou , Theofanis Tsakiris , Carolin Frank , Kevin Vomschee , Svenja Lohmann , Daniel Primetzhofer
We present equipment for sample synthesis, preparation and modification enabling in-situ studies employing medium energy ion beams at the ion implanter facility of the Tandem Laboratory national research infrastructure at Uppsala University. The integral instrumentation enables controlled thin-film synthesis, modification and characterization applicable to study near-surface processes such as thin-film growth, phase transformation, oxidation, annealing, catalysis or ion implantation. We describe the available instrumentation with its specifications and present four demonstrative experiments with a particular focus on the acquired in-situ capabilities addressing 1) Evaporation and thermal alloying of thin films – nickel silicides 2) Reactive magnetron sputtering and controlled oxidization – photochromic YHO 3) Sputtering and low-energy implantation – hydrogen in tungsten and 4) Surface cleaning of sensitive systems – self-supporting silicon membranes.
{"title":"A new system for sample synthesis, preparation and modification combined with in-situ depth profiling using medium energy ions","authors":"Radek Holeňák , Dmitrii Moldarev , Eleni Ntemou , Theofanis Tsakiris , Carolin Frank , Kevin Vomschee , Svenja Lohmann , Daniel Primetzhofer","doi":"10.1016/j.vacuum.2024.113824","DOIUrl":"10.1016/j.vacuum.2024.113824","url":null,"abstract":"<div><div>We present equipment for sample synthesis, preparation and modification enabling <em>in-situ</em> studies employing medium energy ion beams at the ion implanter facility of the Tandem Laboratory national research infrastructure at Uppsala University. The integral instrumentation enables controlled thin-film synthesis, modification and characterization applicable to study near-surface processes such as thin-film growth, phase transformation, oxidation, annealing, catalysis or ion implantation. We describe the available instrumentation with its specifications and present four demonstrative experiments with a particular focus on the acquired <em>in-situ</em> capabilities addressing 1) Evaporation and thermal alloying of thin films – nickel silicides 2) Reactive magnetron sputtering and controlled oxidization – photochromic YHO 3) Sputtering and low-energy implantation – hydrogen in tungsten and 4) Surface cleaning of sensitive systems – self-supporting silicon membranes.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113824"},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.vacuum.2024.113822
Shixian Huang , Hongbo Yao , Helen J. Sun , Hanxi Xiao , Xiao Liu , Chuanbo Hu , Jianting Tang , Joe R. Zhao
Fe-based heterogeneous catalysts are promising in Fenton-like reactions for wastewater treatment, but their practical application is hindered by their recyclability, and the fundamental mechanisms for origin of the high performance and the structure-activity relationships remain to be elucidated further. In this paper, we prepared a series of Fe2(OH)3Cl-containing monolith catalysts by the use of NH4Cl additives, which gave significantly higher performance than the Fe3O4 counterparts in Fenton-like degradation of methylene blue and rhodamine B when H2O2 was used as oxidant. The Fe2(OH)3Cl-containing monolith catalyst can be reused four cycles in the degradation experiments without big loss in their activity. The active radicals generated during process of the catalytic degradation were studied.
{"title":"Fe-based monolithic catalysts for Fenton-like degradation of organic dyes: The important role of Fe2(OH)3Cl species","authors":"Shixian Huang , Hongbo Yao , Helen J. Sun , Hanxi Xiao , Xiao Liu , Chuanbo Hu , Jianting Tang , Joe R. Zhao","doi":"10.1016/j.vacuum.2024.113822","DOIUrl":"10.1016/j.vacuum.2024.113822","url":null,"abstract":"<div><div>Fe-based heterogeneous catalysts are promising in Fenton-like reactions for wastewater treatment, but their practical application is hindered by their recyclability, and the fundamental mechanisms for origin of the high performance and the structure-activity relationships remain to be elucidated further. In this paper, we prepared a series of Fe<sub>2</sub>(OH)<sub>3</sub>Cl-containing monolith catalysts by the use of NH<sub>4</sub>Cl additives, which gave significantly higher performance than the Fe<sub>3</sub>O<sub>4</sub> counterparts in Fenton-like degradation of methylene blue and rhodamine B when H<sub>2</sub>O<sub>2</sub> was used as oxidant. The Fe<sub>2</sub>(OH)<sub>3</sub>Cl-containing monolith catalyst can be reused four cycles in the degradation experiments without big loss in their activity. The active radicals generated during process of the catalytic degradation were studied.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"232 ","pages":"Article 113822"},"PeriodicalIF":3.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.vacuum.2024.113819
Guoqing Feng , Tiewei Zhao , Lingling Zhou , Xin Wang , Hao Ding , Feng Jiang , Huiyu Li , Yongsheng Liu , Qing Yu , Haijing Cao , Yan Xu , Yanyan Zhu
Transition metal sulfides have attracted considerable attention as supercapacitor materials due to their favorable electrochemical properties and low cost. However, challenges such as slow electrochemical kinetics and significant volume changes still persist. In this study, (FeMn)S2@NC nanocubes were synthesized by utilizing MOFs as precursors, employing a solution method to encapsulate Ppy around the periphery, followed by a one-step annealing process. The electrode prepared from (FeMn)S2@NC exhibits a high specific capacitance of 1154 F/g at 1 A/g and retains a specific capacitance of 777 F/g even at a high current density of 5 A/g. After 8000 charge-discharge cycles at 10 A/g, it still maintains a high capacity retention of 94 % and close to 100 % Coulombic efficiency. The (FeMn)S2@NC//AC capacitor exhibite excellent electrochemical performance with good rate capability and practical value 39.73F/g at 1A/g, 38.26F/g at 2A/g, 26.67F/g at 5A/g, 20.53F/g at 7A/g and 14F/g at 10A/g. Electrochemical testing at 5A/g show 93.3 % high capacity retention after 180,000 cycles.
{"title":"Nanocubic transition metal sulfides (FeMn)S2@NC synthesized by MOFs facily for supercapacitors","authors":"Guoqing Feng , Tiewei Zhao , Lingling Zhou , Xin Wang , Hao Ding , Feng Jiang , Huiyu Li , Yongsheng Liu , Qing Yu , Haijing Cao , Yan Xu , Yanyan Zhu","doi":"10.1016/j.vacuum.2024.113819","DOIUrl":"10.1016/j.vacuum.2024.113819","url":null,"abstract":"<div><div>Transition metal sulfides have attracted considerable attention as supercapacitor materials due to their favorable electrochemical properties and low cost. However, challenges such as slow electrochemical kinetics and significant volume changes still persist. In this study, (FeMn)S<sub>2</sub>@NC nanocubes were synthesized by utilizing MOFs as precursors, employing a solution method to encapsulate Ppy around the periphery, followed by a one-step annealing process. The electrode prepared from (FeMn)S2@NC exhibits a high specific capacitance of 1154 F/g at 1 A/g and retains a specific capacitance of 777 F/g even at a high current density of 5 A/g. After 8000 charge-discharge cycles at 10 A/g, it still maintains a high capacity retention of 94 % and close to 100 % Coulombic efficiency. The (FeMn)S2@NC//AC capacitor exhibite excellent electrochemical performance with good rate capability and practical value 39.73F/g at 1A/g, 38.26F/g at 2A/g, 26.67F/g at 5A/g, 20.53F/g at 7A/g and 14F/g at 10A/g. Electrochemical testing at 5A/g show 93.3 % high capacity retention after 180,000 cycles.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113819"},"PeriodicalIF":3.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.vacuum.2024.113817
Y. Meng , G.X. zhang , D.W. Chen , M. Xu , Q.W. Liu , F.C. Jiao
In this study, a Z-scheme heterojunction CoFe1.95Y0.05O4/Ag/g-C3N4 (CFYO/ACN) magnetic nanocomposite was prepared by hydrothermal synthesis. The composite was characterised and analyzed using different characterization tools and its photocatalytic degradation activity towards methylene blue (MB) was investigated. The results showed that the CFYO/ACN photocatalyst compared to CoFe1.95Y0.05O4 (CFYO) and Ag/g-C3N4 (ACN), the composite CFYO/ACN had the highest degradation efficiency of MB, which was up to 97 % within 120 min, which was 1.26 and 1.09 times higher than that of ACN and CFYO, respectively. The enhancement of the catalytic performance of CFYO/ACN was attributed to the fact that the heterogeneous junction formation effectively inhibited the complexation of photogenerated carriers. In addition, five consecutive cyclic degradation experiments showed that CFYO/ACN exhibited efficient photocatalytic degradation, stable crystal structure, and easy recycling in the photodegradation process. Finally, the capture experiments confirmed that superoxide radicals () and hydroxyl radicals (·OH) play a major role in the degradation process. This study provides an effective strategy for the construction of efficient photocatalysts.
{"title":"Construction and degradation mechanism of the magnetic CoFe1.95Y0.05O4/Ag/g-C3N4 Z-scheme heterojunction for enhanced photocatalytic activity","authors":"Y. Meng , G.X. zhang , D.W. Chen , M. Xu , Q.W. Liu , F.C. Jiao","doi":"10.1016/j.vacuum.2024.113817","DOIUrl":"10.1016/j.vacuum.2024.113817","url":null,"abstract":"<div><div>In this study, a Z-scheme heterojunction CoFe<sub>1.95</sub>Y<sub>0.05</sub>O<sub>4</sub>/Ag/g-C<sub>3</sub>N<sub>4</sub> (CFYO/ACN) magnetic nanocomposite was prepared by hydrothermal synthesis. The composite was characterised and analyzed using different characterization tools and its photocatalytic degradation activity towards methylene blue (MB) was investigated. The results showed that the CFYO/ACN photocatalyst compared to CoFe<sub>1.95</sub>Y<sub>0.05</sub>O<sub>4</sub> (CFYO) and Ag/g-C<sub>3</sub>N<sub>4</sub> (ACN), the composite CFYO/ACN had the highest degradation efficiency of MB, which was up to 97 % within 120 min, which was 1.26 and 1.09 times higher than that of ACN and CFYO, respectively. The enhancement of the catalytic performance of CFYO/ACN was attributed to the fact that the heterogeneous junction formation effectively inhibited the complexation of photogenerated carriers. In addition, five consecutive cyclic degradation experiments showed that CFYO/ACN exhibited efficient photocatalytic degradation, stable crystal structure, and easy recycling in the photodegradation process. Finally, the capture experiments confirmed that superoxide radicals (<span><math><mrow><mo>⋅</mo><msubsup><mi>O</mi><mn>2</mn><mo>−</mo></msubsup></mrow></math></span>) and hydroxyl radicals (·OH) play a major role in the degradation process. This study provides an effective strategy for the construction of efficient photocatalysts.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113817"},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.vacuum.2024.113815
Yantao Li , Ziyuan Luo , Hua Lan , Jun Liang , Deming Huang , Yu Ni , Donglin Ma , Xin Jiang
In this paper, we designed a FeCoNiCu high-entropy system composed of elements with weak nitride-forming tendencies. The (FeCoNiCu)Nx high-entropy films (HEFs) were fabricated using high-power pulsed magnetron sputtering (HPPMS) by adjusting the nitrogen flow rate, and the film structure and mechanical properties were systematically investigated. Upon the introduction of N atoms, the film gradually transitioned from an FCC single-phase to a simple cubic structure, accompanied by an increase in grain size. The simple cubic phase represents a multi-component phase, where N atoms are incorporated into the FeCoNiCu lattice. XPS analysis reveals that all four elements—Fe, Co, Ni, and Cu—combine with N to form weak covalent bonds. As the N content in the film increases, the hardness of the simple cubic (FeCoNiCu)Nx film increased by 33 % compared to the FeCoNiCu alloy film, from 7.9 to 10.5 GPa, which is attributed to the solid solution strengthening effect and phase transition. This work offers new insights into the structural evolution of high-entropy alloy systems composed of weak nitride-forming elements.
本文设计了一种由具有弱氮化物形成倾向的元素组成的铁钴镍铜高熵体系。通过调节氮气流速,利用高功率脉冲磁控溅射(HPPMS)技术制备了(FeCoNiCu)Nx 高熵薄膜(HEFs),并对薄膜的结构和力学性能进行了系统研究。引入 N 原子后,薄膜从 FCC 单相逐渐过渡到简单立方结构,同时晶粒尺寸增大。简单立方相代表了一种多组分相,其中 N 原子融入了铁钴镍铜晶格中。XPS 分析显示,所有四种元素--铁、钴、镍和铜--都与 N 结合形成弱共价键。随着薄膜中 N 含量的增加,简单立方 (FeCoNiCu)Nx 薄膜的硬度比 FeCoNiCu 合金薄膜提高了 33%,从 7.9 GPa 提高到 10.5 GPa,这归因于固溶强化效应和相变。这项研究为了解由弱氮化物形成元素组成的高熵合金体系的结构演变提供了新的视角。
{"title":"Study on the structure evolution of (FeCoNiCu)Nx high-entropy thin film","authors":"Yantao Li , Ziyuan Luo , Hua Lan , Jun Liang , Deming Huang , Yu Ni , Donglin Ma , Xin Jiang","doi":"10.1016/j.vacuum.2024.113815","DOIUrl":"10.1016/j.vacuum.2024.113815","url":null,"abstract":"<div><div>In this paper, we designed a FeCoNiCu high-entropy system composed of elements with weak nitride-forming tendencies. The (FeCoNiCu)N<sub>x</sub> high-entropy films (HEFs) were fabricated using high-power pulsed magnetron sputtering (HPPMS) by adjusting the nitrogen flow rate, and the film structure and mechanical properties were systematically investigated. Upon the introduction of N atoms, the film gradually transitioned from an FCC single-phase to a simple cubic structure, accompanied by an increase in grain size. The simple cubic phase represents a multi-component phase, where N atoms are incorporated into the FeCoNiCu lattice. XPS analysis reveals that all four elements—Fe, Co, Ni, and Cu—combine with N to form weak covalent bonds. As the N content in the film increases, the hardness of the simple cubic (FeCoNiCu)N<sub>x</sub> film increased by 33 % compared to the FeCoNiCu alloy film, from 7.9 to 10.5 GPa, which is attributed to the solid solution strengthening effect and phase transition. This work offers new insights into the structural evolution of high-entropy alloy systems composed of weak nitride-forming elements.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113815"},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.vacuum.2024.113810
Zhaoqi Hou , Tao Wang , Peipei Wang , Yuhao Wu , Wanchang Sun
The nanometallic Ti and Zr monolayer films with various thicknesses ranging from 600 to 2200 nm were prepared by using magnetron sputtering technique. The microstructure results demonstrated that Ti films transformed from hcp to fcc at t ≤ 600 nm, while Zr films were grown with hcp structure of nanocolumnar grain. Moreover, the grain orientation of hcp Ti films changed from (0002) preferred orientation at t = 1200 nm to random orientation at larger thickness. Subsequently, the hardness and strain rate sensitivity of films were explored by nanoindentation. The Hall-Petch relationship is obviously invalid to explain the film thickness dependent hardening behaviors in Ti and Zr films, and the influence of phase structure, orientation and residual stress on nanoindentation hardness was discussed. It seems that residual stress plays an important role in the determination of hardness in present Ti and Zr films. The negative strain rate sensitivity m appeared during the plastic deformation of fcc Ti films, which is caused by the phase transformation. The underlying deformation mechanism of hcp Ti and Zr films was also discussed.
利用磁控溅射技术制备了不同厚度(从 600 纳米到 2200 纳米)的纳米金属钛和锆单层薄膜。显微结构结果表明,Ti 薄膜在 t ≤ 600 nm 时由 hcp 转变为 fcc,而 Zr 薄膜则生长为纳米柱状晶粒的 hcp 结构。此外,hcp Ti 薄膜的晶粒取向从 t = 1200 nm 时的(0002)优先取向转变为厚度较大时的无规取向。随后,通过纳米压痕法探究了薄膜的硬度和应变速率敏感性。霍尔-佩奇关系显然无法解释钛和锆薄膜随厚度变化的硬化行为,因此讨论了相结构、取向和残余应力对纳米压痕硬度的影响。看来残余应力在目前钛和锆薄膜硬度的决定中起着重要作用。在 fcc Ti 薄膜的塑性变形过程中出现了负应变速率灵敏度 m,这是由相变引起的。此外,还讨论了 hcp Ti 和 Zr 薄膜的基本变形机制。
{"title":"Size dependent mechanical properties and deformation mechanisms in Ti and Zr films","authors":"Zhaoqi Hou , Tao Wang , Peipei Wang , Yuhao Wu , Wanchang Sun","doi":"10.1016/j.vacuum.2024.113810","DOIUrl":"10.1016/j.vacuum.2024.113810","url":null,"abstract":"<div><div>The nanometallic Ti and Zr monolayer films with various thicknesses ranging from 600 to 2200 nm were prepared by using magnetron sputtering technique. The microstructure results demonstrated that Ti films transformed from hcp to fcc at <em>t</em> ≤ 600 nm, while Zr films were grown with hcp structure of nanocolumnar grain. Moreover, the grain orientation of hcp Ti films changed from (0002) preferred orientation at <em>t</em> = 1200 nm to random orientation at larger thickness. Subsequently, the hardness and strain rate sensitivity of films were explored by nanoindentation. The Hall-Petch relationship is obviously invalid to explain the film thickness dependent hardening behaviors in Ti and Zr films, and the influence of phase structure, orientation and residual stress on nanoindentation hardness was discussed. It seems that residual stress plays an important role in the determination of hardness in present Ti and Zr films. The negative strain rate sensitivity <em>m</em> appeared during the plastic deformation of fcc Ti films, which is caused by the phase transformation. The underlying deformation mechanism of hcp Ti and Zr films was also discussed.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113810"},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-07DOI: 10.1016/j.vacuum.2024.113813
Yuchong Chen , Yubo Wang , Zaijiu Li , Yue Shen , Ming Wen , Sugun Lim , Qinglin Jin
This study investigates the effects of vacuum and hydrogen atmospheres on the removal of metallic and non-metallic impurities during zone melting of Al, Cu, and Ni. The results show that while hydrogen had minimal impact on metallic impurity removal, it significantly enhanced the elimination of non-metallic impurities, particularly oxygen, in Cu and Ni. The introduction of hydrogen reduced oxygen levels by over 95 % in Ni and 44 % in Cu, and also improved the removal of carbon and sulfur. However, in Al, hydrogen refining proved less effective due to the stability of Al₂O₃ and the tendency of Al to form hydrides.
{"title":"Comparative analysis of impurity removal in aluminum, copper, and nickel by hydrogen refining","authors":"Yuchong Chen , Yubo Wang , Zaijiu Li , Yue Shen , Ming Wen , Sugun Lim , Qinglin Jin","doi":"10.1016/j.vacuum.2024.113813","DOIUrl":"10.1016/j.vacuum.2024.113813","url":null,"abstract":"<div><div>This study investigates the effects of vacuum and hydrogen atmospheres on the removal of metallic and non-metallic impurities during zone melting of Al, Cu, and Ni. The results show that while hydrogen had minimal impact on metallic impurity removal, it significantly enhanced the elimination of non-metallic impurities, particularly oxygen, in Cu and Ni. The introduction of hydrogen reduced oxygen levels by over 95 % in Ni and 44 % in Cu, and also improved the removal of carbon and sulfur. However, in Al, hydrogen refining proved less effective due to the stability of Al₂O₃ and the tendency of Al to form hydrides.</div></div>","PeriodicalId":23559,"journal":{"name":"Vacuum","volume":"231 ","pages":"Article 113813"},"PeriodicalIF":3.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}