Pub Date : 2024-10-16DOI: 10.1016/j.physb.2024.416635
Y-type Ba0.5Sr1.5Zn2Fe12-xGaxO22 (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) hexaferrites are prepared through modified chemical co-precipitation method. X-ray diffraction (XRD) results reveal that these samples are single-phase and the space group is . The field-emission scanning electronic microscope (FE-SEM) measurements indicate that the grains are hexagonal-plate with a diameter of 2–5 μm. In the M-T diagrams, various magnetic structures are modulated, including proper-screw, longitudinal conical (LC), mixed conical (MC), and collinear ferrimagnetic (collinear FIM). In this series of samples, the values of dielectric constant () achieve an order increase from 102 to 104. For the best x = 0.8 sample, the is as high as 1804.76 at 1 MHz and 300 K. In conclusion, Ba0.5Sr1.5Zn2Fe12-xGaxO22 with controllable magnetic structures and colossal dielectric constant are potential materials for miniaturization of modern electronic devices.
{"title":"Magnetic structure and colossal dielectric properties in Ga3+ substituted Zn2Y hexaferrites by chemical co-precipitation method","authors":"","doi":"10.1016/j.physb.2024.416635","DOIUrl":"10.1016/j.physb.2024.416635","url":null,"abstract":"<div><div>Y-type Ba<sub>0.5</sub>Sr<sub>1.5</sub>Zn<sub>2</sub>Fe<sub>12-<em>x</em></sub>Ga<sub><em>x</em></sub>O<sub>22</sub> (<em>x</em> = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) hexaferrites are prepared through modified chemical co-precipitation method. X-ray diffraction (XRD) results reveal that these samples are single-phase and the space group is <span><math><mrow><mi>R</mi><mover><mn>3</mn><mo>‾</mo></mover><mi>m</mi></mrow></math></span>. The field-emission scanning electronic microscope (FE-SEM) measurements indicate that the grains are hexagonal-plate with a diameter of 2–5 μm. In the <em>M-T</em> diagrams, various magnetic structures are modulated, including proper-screw, longitudinal conical (LC), mixed conical (MC), and collinear ferrimagnetic (collinear FIM). In this series of samples, the values of dielectric constant (<span><math><mrow><msup><mi>ε</mi><mo>′</mo></msup></mrow></math></span>) achieve an order increase from 10<sup>2</sup> to 10<sup>4</sup>. For the best <em>x</em> = 0.8 sample, the <span><math><mrow><msup><mi>ε</mi><mo>′</mo></msup></mrow></math></span> is as high as 1804.76 at 1 MHz and 300 K. In conclusion, Ba<sub>0.5</sub>Sr<sub>1.5</sub>Zn<sub>2</sub>Fe<sub>12-<em>x</em></sub>Ga<sub><em>x</em></sub>O<sub>22</sub> with controllable magnetic structures and colossal dielectric constant are potential materials for miniaturization of modern electronic devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446596","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}
Pub Date : 2024-10-15DOI: 10.1016/j.physb.2024.416629
Herein, the optical, electronic and magnetic properties of Mg1-xMnxS alloys are computed by employing density functional theory. The full-potential linearized augmented plane wave (FP-LAPW) method was used within the frame work of Wein2k to explore spin polarized band structure along with total and partial density of states. The results of spin polarized band structure calculations exhibited semiconducting character in both spin states. The net magnetic moment (μB) is primarily credited to presence of partially filled 3d state of Mn atom. μB gives evidence of p-d hybridization between orbitals of Mn and parent lattice ions. Optical characteristics of Mg1-xMnxS including dielectric constants along with relevant features have been reported at 0–10 eV energy range. High value of absorption coefficient and smaller reflectance in ultraviolet energy span suggests potentiality of doped alloy for optoelectronic applications. Moreover, ferromagnetic character makes it suitable for spintronic storage devices.
本文采用密度泛函理论计算了 Mg1-xMnxS 合金的光学、电子和磁学特性。在 Wein2k 的框架内使用了全电位线性化增强平面波(FP-LAPW)方法来探索自旋极化带结构以及总态密度和部分态密度。自旋极化带结构计算的结果表明,两种自旋态都具有半导体特性。净磁矩(μB)主要归功于锰原子部分填充 3d 态的存在。据报道,Mg1-xMnxS 的光学特性包括介电常数以及 0-10 eV 能量范围内的相关特征。紫外线能量范围内的高吸收系数和较小的反射率表明,掺杂合金具有光电应用的潜力。此外,铁磁特性也使其适用于自旋电子存储设备。
{"title":"Investigation of magneto-optoelectronics properties of Mg1-xMnxS alloys for optoelectronics and spintronic applications","authors":"","doi":"10.1016/j.physb.2024.416629","DOIUrl":"10.1016/j.physb.2024.416629","url":null,"abstract":"<div><div>Herein, the optical, electronic and magnetic properties of Mg<sub>1-x</sub>Mn<sub>x</sub>S alloys are computed by employing density functional theory. The full-potential linearized augmented plane wave (FP-LAPW) method was used within the frame work of Wein2k to explore spin polarized band structure along with total and partial density of states. The results of spin polarized band structure calculations exhibited semiconducting character in both spin states. The net magnetic moment (μ<sub>B</sub>) is primarily credited to presence of partially filled 3d state of Mn atom. μ<sub>B</sub> gives evidence of <em>p-d</em> hybridization between orbitals of Mn and parent lattice ions. Optical characteristics of Mg<sub>1-x</sub>Mn<sub>x</sub>S including dielectric constants along with relevant features have been reported at 0–10 eV energy range. High value of absorption coefficient and smaller reflectance in ultraviolet energy span suggests potentiality of doped alloy for optoelectronic applications. Moreover, ferromagnetic character makes it suitable for spintronic storage devices.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446595","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}
Pub Date : 2024-10-13DOI: 10.1016/j.physb.2024.416628
Persistence luminescence (PerL) and thermoluminescence (TL) of BaAl2O4 - BaAl12O19 mixedphase compound under 260 nm UVC irradiation are studied. The sample shows PerL for more than 1 h post irradiation. TL glow curves of the sample recorded at 1 oC/s following irradiation to UVC radiation shows a composite glow peak between 30 and 230 °C. The TL intensity is found to be affected by thermal quenching. The activation energy for thermal quenching is estimated to be W = 0.85 ± 0.12 eV. A Tm-Tstop analysis reveals that the TL glow peak is composed of multiple first order components. The activation energy associated with the electron traps are found to vary from 0.66 to 1.70 eV. The density of the traps is high between 0.60 and 1.20 eV. Due to presence of continuous distribution of electron traps, there is an excellent scope of developing colour tuneable persistence luminescence phosphor using mixed phase barium aluminate.
研究了在 260 纳米紫外线照射下 BaAl2O4 - BaAl12O19 混相化合物的持续发光(PerL)和热发光(TL)。样品在辐照后 1 小时以上都显示 PerL。样品在接受紫外线照射后以 1 oC/s 的速度记录的 TL 辉光曲线显示出 30 至 230 °C 之间的复合辉光峰。热淬火会影响 TL 强度。热淬火的活化能估计为 W = 0.85 ± 0.12 eV。Tm-Tstop 分析显示,TL 辉光峰由多个一阶成分组成。发现与电子陷阱相关的活化能在 0.66 至 1.70 eV 之间变化。陷阱密度在 0.60 至 1.20 eV 之间较高。由于存在连续分布的电子陷阱,使用混合相铝酸钡开发颜色可调的持久发光荧光粉具有广阔的前景。
{"title":"Persistence luminescence and thermoluminescence of 260 nm UVC irradiated mixed-phase (BaAl2O4 - BaAl12O19) barium aluminate","authors":"","doi":"10.1016/j.physb.2024.416628","DOIUrl":"10.1016/j.physb.2024.416628","url":null,"abstract":"<div><div>Persistence luminescence (PerL) and thermoluminescence (TL) of BaAl<sub>2</sub>O<sub>4</sub> - BaAl<sub>12</sub>O<sub>19</sub> mixedphase compound under 260 nm UVC irradiation are studied. The sample shows PerL for more than 1 h post irradiation. TL glow curves of the sample recorded at 1 <sup>o</sup>C/s following irradiation to UVC radiation shows a composite glow peak between 30 and 230 °C. The TL intensity is found to be affected by thermal quenching. The activation energy for thermal quenching is estimated to be <em>W</em> = 0.85 ± 0.12 eV. A <em>T</em><sub>m</sub>-<em>T</em><sub>stop</sub> analysis reveals that the TL glow peak is composed of multiple first order components. The activation energy associated with the electron traps are found to vary from 0.66 to 1.70 eV. The density of the traps is high between 0.60 and 1.20 eV. Due to presence of continuous distribution of electron traps, there is an excellent scope of developing colour tuneable persistence luminescence phosphor using mixed phase barium aluminate.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433779","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}
Pub Date : 2024-10-13DOI: 10.1016/j.physb.2024.416627
Sol-gel and electrospinning methods successfully prepared porous TiO2 fibers. The samples were calcined at temperatures of 450 °C and 550 °C and characterized using different techniques. XRD analysis also revealed crystalline anatase and rutile phases of mp-TiO2 observed at calcining temperatures of 450 °C and 550 °C, whereas as-prepared showed an amorphous-like structure. Relatively higher surface area and photocatalytic efficiency were increased with a decrease in crystallite size. All samples absorb UV region. The Rs value of TiO2 calcined at 550 °C was 16.6 Ω, which is much lower than those of the 450 °C calcined TiO2 powder electrode (52.7 Ω) and as-prepared TiO2 electrode (95.3 Ω). In addition, the Rp resistance of TiO2 calcined at 550 °C electrode (5.85 kΩ) was also lower than those of 450 °C calcined TiO2 powder (39.0 kΩ) and as-prepared TiO2 electrode (68.9 kΩ), revealing better electronic and ionic conduction of TiO2 calcined at 550 °C electrode.
{"title":"Synthesis, characterization, electrochemical impedance spectroscopy performance and photodegradation of methylene blue: Mesoporous PEG/TiO2 by sol-gel electrospinning","authors":"","doi":"10.1016/j.physb.2024.416627","DOIUrl":"10.1016/j.physb.2024.416627","url":null,"abstract":"<div><div>Sol-gel and electrospinning methods successfully prepared porous TiO<sub>2</sub> fibers. The samples were calcined at temperatures of 450 °C and 550 °C and characterized using different techniques. XRD analysis also revealed crystalline anatase and rutile phases of mp-TiO<sub>2</sub> observed at calcining temperatures of 450 °C and 550 °C, whereas as-prepared showed an amorphous-like structure. Relatively higher surface area and photocatalytic efficiency were increased with a decrease in crystallite size. All samples absorb UV region. The Rs value of TiO<sub>2</sub> calcined at 550 °C was 16.6 Ω, which is much lower than those of the 450 °C calcined TiO<sub>2</sub> powder electrode (52.7 Ω) and as-prepared TiO<sub>2</sub> electrode (95.3 Ω). In addition, the Rp resistance of TiO<sub>2</sub> calcined at 550 °C electrode (5.85 kΩ) was also lower than those of 450 °C calcined TiO<sub>2</sub> powder (39.0 kΩ) and as-prepared TiO<sub>2</sub> electrode (68.9 kΩ), revealing better electronic and ionic conduction of TiO<sub>2</sub> calcined at 550 °C electrode.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-10-12DOI: 10.1016/j.physb.2024.416618
Currently, research has been conducted on the individual oxides La2W2O9 and Fe2O3 but not on its composite form. Using a solid-state reaction technique, a La2W2O9/Fe2O3 composite was created. A particular calcination cycle was followed by mixing the raw precursors. Scanning electron microscopy (SEM) was used to investigate the morphological microstructure, and X-ray diffraction (XRD) was used to examine the structural characteristics. The thermal and gravimetric properties were examined via differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The optical characteristics were investigated via UV–visible spectroscopy, which investigated included the transmittance, absorbance, absorption coefficient, band gap (Eg), penetration depth (β), Urbach energy (EU), refractive index, optical conductivity, and dielectric function. These findings indicate that the optical properties improved after the addition of Fe2O3 compared with those of pure La2W2O9. The La2W2O9/Fe2O3 composite holds promise as a prospective material for use in the fields of sunscreen products, UV shielding or solar filtration.
{"title":"Structural, morphological and optical properties of the La2W2O9/Fe2O3 composite for UV-shielding applications","authors":"","doi":"10.1016/j.physb.2024.416618","DOIUrl":"10.1016/j.physb.2024.416618","url":null,"abstract":"<div><div>Currently, research has been conducted on the individual oxides La<sub>2</sub>W<sub>2</sub>O<sub>9</sub> and Fe<sub>2</sub>O<sub>3</sub> but not on its composite form. Using a solid-state reaction technique, a La<sub>2</sub>W<sub>2</sub>O<sub>9</sub>/Fe<sub>2</sub>O<sub>3</sub> composite was created. A particular calcination cycle was followed by mixing the raw precursors. Scanning electron microscopy (SEM) was used to investigate the morphological microstructure, and X-ray diffraction (XRD) was used to examine the structural characteristics. The thermal and gravimetric properties were examined via differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The optical characteristics were investigated via UV–visible spectroscopy, which investigated included the transmittance, absorbance, absorption coefficient, band gap (E<sub>g</sub>), penetration depth (β), Urbach energy (E<sub>U</sub>), refractive index, optical conductivity, and dielectric function. These findings indicate that the optical properties improved after the addition of Fe<sub>2</sub>O<sub>3</sub> compared with those of pure La<sub>2</sub>W<sub>2</sub>O<sub>9</sub>. The La<sub>2</sub>W<sub>2</sub>O<sub>9</sub>/Fe<sub>2</sub>O<sub>3</sub> composite holds promise as a prospective material for use in the fields of sunscreen products, UV shielding or solar filtration.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442319","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}
Pub Date : 2024-10-12DOI: 10.1016/j.physb.2024.416625
Tin oxide nanoparticles (SnO2 NPs), both pure and doped with Group VI (G6) metal ions (Cr+3, Mo+5, and W+6), were synthesized using pulsed laser ablation in liquid. This study aimed to investigate the effect of G6 doping on the electronic properties of SnO2 NPs, with an emphasis on enhancing their photoluminescence for optoelectronic applications. Transmission electron microscopy revealed well-crystallized samples with diameters of 3–6 nm, indicating quantum-confinement effects. The optical band gap, determined by UV–Vis spectroscopy, was reduced from 5.1 eV (undoped) to 4.9 eV (Cr-doped) due to defect states, while increasing to 5.3 eV and 5.7 eV for Mo- and W-doped SnO2, respectively, due to the Moss-Burstein effect. The photoluminescence spectra exhibited a redshift, with strong red emission around 700 nm, which was up to 90 % more intense than that of the undoped SnO2. This enhancement was attributed to the 2E→4A2 transition and increased defect states.
{"title":"Photoluminescence properties of SnO2 nanoparticles doped with group VI elements (Cr, Mo, W) synthesized by pulsed laser ablation in liquid","authors":"","doi":"10.1016/j.physb.2024.416625","DOIUrl":"10.1016/j.physb.2024.416625","url":null,"abstract":"<div><div>Tin oxide nanoparticles (SnO<sub>2</sub> NPs), both pure and doped with Group VI (G6) metal ions (Cr<sup>+3</sup>, Mo<sup>+5</sup>, and W<sup>+6</sup>), were synthesized using pulsed laser ablation in liquid. This study aimed to investigate the effect of G6 doping on the electronic properties of SnO<sub>2</sub> NPs, with an emphasis on enhancing their photoluminescence for optoelectronic applications. Transmission electron microscopy revealed well-crystallized samples with diameters of 3–6 nm, indicating quantum-confinement effects. The optical band gap, determined by UV–Vis spectroscopy, was reduced from 5.1 <em>e</em>V (undoped) to 4.9 <em>e</em>V (Cr-doped) due to defect states, while increasing to 5.3 <em>e</em>V and 5.7 <em>e</em>V for Mo- and W-doped SnO<sub>2</sub>, respectively, due to the Moss-Burstein effect. The photoluminescence spectra exhibited a redshift, with strong red emission around 700 nm, which was up to 90 % more intense than that of the undoped SnO<sub>2</sub>. This enhancement was attributed to the <sup>2</sup>E→<sup>4</sup>A<sub>2</sub> transition and increased defect states.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446536","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}
Pub Date : 2024-10-12DOI: 10.1016/j.physb.2024.416623
The structure of gradient rhabdophane nanoparticles of variable composition (La,Y)PO4·nH2O obtained by precipitation is considered. According to the data of HAADF TEM and EDX mapping using the Abel inversion procedure, it was shown that there is an inhomogeneous distribution of yttrium and lanthanum atoms in the particles from the central part to the periphery. At the same time, the nominal composition of both individual nanoparticles and the entire sample meets the value specified during synthesis within the error of the method – La0.27Y0.73PO4·nH2O. According to SAXS data, it was determined that in the particles of (La,Y)PO4·nH2O, there is a redistribution of scattering densities, which is caused by an increase in the fraction of YPO4 in the peripheral region of the particles. The observed effect of the distribution of cations over the particle made it possible to determine the size of the gradient layer, which reaches 50 % of the total particle size.
{"title":"Gradient distribution of cations in rhabdophane La0.27Y0.73PO4·nH2O nanoparticles","authors":"","doi":"10.1016/j.physb.2024.416623","DOIUrl":"10.1016/j.physb.2024.416623","url":null,"abstract":"<div><div>The structure of gradient rhabdophane nanoparticles of variable composition (La,Y)PO<sub>4</sub>·<em>n</em>H<sub>2</sub>O obtained by precipitation is considered. According to the data of HAADF TEM and EDX mapping using the Abel inversion procedure, it was shown that there is an inhomogeneous distribution of yttrium and lanthanum atoms in the particles from the central part to the periphery. At the same time, the nominal composition of both individual nanoparticles and the entire sample meets the value specified during synthesis within the error of the method – La<sub>0.27</sub>Y<sub>0.73</sub>PO<sub>4</sub>·<em>n</em>H<sub>2</sub>O. According to SAXS data, it was determined that in the particles of (La,Y)PO<sub>4</sub>·<em>n</em>H<sub>2</sub>O, there is a redistribution of scattering densities, which is caused by an increase in the fraction of YPO<sub>4</sub> in the peripheral region of the particles. The observed effect of the distribution of cations over the particle made it possible to determine the size of the gradient layer, which reaches 50 % of the total particle size.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441703","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}
Pub Date : 2024-10-11DOI: 10.1016/j.physb.2024.416616
Cobalt molybdate (CoMoO4) and its rare earth doped variants have emerged as promising photocatalysts for degrading dye pollutants in wastewater. The photocatalysts were prepared using a modified sol-gel method, employing ammonium heptamolybdate tetrahydrate and cobalt (II) nitrate hexahydrate as precursors. The incorporation of samarium and erbium as a dopant was hypothesized to improve the photocatalytic activity of CoMoO4 by altering its band structure and creating defect sites for improved dye adsorption and degradation. The structural and optical properties of the synthesized photocatalysts were characterized using various techniques. The photocatalytic performance of CoMoO4, Sm:CoMoO4 and Er:CoMoO4 was evaluated by monitoring the degradation of MB dye under light irradiation. The results reveal that Sm:CoMoO4 and Er:CoMoO4 catalysts achieve a degradation efficiencies of 99 % and 97 %, respectively, highlighting the potential of rare earth-doped CoMoO4 as an efficient photocatalyst for the remediation of dye contaminated wastewater.
{"title":"Investigation of rare earth metal ions (Sm and Er) doped CoMoO4 polymorphs for photocatalytic dye degradation","authors":"","doi":"10.1016/j.physb.2024.416616","DOIUrl":"10.1016/j.physb.2024.416616","url":null,"abstract":"<div><div>Cobalt molybdate (CoMoO<sub>4</sub>) and its rare earth doped variants have emerged as promising photocatalysts for degrading dye pollutants in wastewater. The photocatalysts were prepared using a modified sol-gel method, employing ammonium heptamolybdate tetrahydrate and cobalt (II) nitrate hexahydrate as precursors. The incorporation of samarium and erbium as a dopant was hypothesized to improve the photocatalytic activity of CoMoO<sub>4</sub> by altering its band structure and creating defect sites for improved dye adsorption and degradation. The structural and optical properties of the synthesized photocatalysts were characterized using various techniques. The photocatalytic performance of CoMoO<sub>4</sub>, Sm:CoMoO<sub>4</sub> and Er:CoMoO<sub>4</sub> was evaluated by monitoring the degradation of MB dye under light irradiation. The results reveal that Sm:CoMoO<sub>4</sub> and Er:CoMoO<sub>4</sub> catalysts achieve a degradation efficiencies of 99 % and 97 %, respectively, highlighting the potential of rare earth-doped CoMoO<sub>4</sub> as an efficient photocatalyst for the remediation of dye contaminated wastewater.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425058","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}
Pub Date : 2024-10-11DOI: 10.1016/j.physb.2024.416615
Fe3GaTe2, with intrinsic magnetism at ambient temperature and high perpendicular magnetic anisotropy, is a promising van der Waals material for 2D-materials-based spintronic devices. Herein, we report the anisotropic magnetocaloric effects and magnetic critical phenomena in Fe3GaTe2 single crystal. Owing to the large anisotropy, magnetic entropy change shows anisotropic character with of 1.67 J kg−1 K−1 along the c axis and 1.11 J kg−1 K−1 in the ab plane under field change of 5 T. The rotating from the ab plane to the c axis reaches 0.67 J kg−1 K−1 at magnetic field of 5 T. By carefully fitting the and relative cooling power (RCP), we determine their relationships to be (n = 0.694(1)) and (m = 1.301(3)) for the magnetic field along the c-axis. Further analysis of critical behavior near TC reveals critical exponents β = 0.41(1) at TC = 341.5(1) K, γ = 1.01(1) at TC = 341.6(3) K, and δ = 3.67(15) at TC = 340 K, indicating a three-dimensional complex magnetic exchange.
Fe3GaTe2 在常温下具有本征磁性和高垂直磁各向异性,是一种很有前途的范德华材料,可用于基于二维材料的自旋电子器件。在此,我们报告了 Fe3GaTe2 单晶的各向异性磁致效应和磁临界现象。由于存在较大的各向异性,磁熵变化(-ΔSM)呈现出各向异性的特征,在磁场变化为 5 T 时,沿 c 轴的-ΔSM 最大值为 1.67 J kg-1 K-1,在 ab 平面上为 1.11 J kg-1 K-1。通过仔细拟合-ΔSMmax 和相对冷却功率 (RCP),我们确定它们在沿 c 轴的磁场中的关系为 -ΔSMmax∝Hn (n = 0.694(1)) 和 RCP∝Hm (m = 1.301(3))。对 TC 附近临界行为的进一步分析表明,在 TC = 341.5(1) K 时,临界指数 β = 0.41(1);在 TC = 341.6(3) K 时,临界指数 γ = 1.01(1);在 TC = 340 K 时,临界指数 δ = 3.67(15),表明存在三维复合磁交换。
{"title":"Anisotropic magnetic entropy change and magnetic critical behavior in van der Waals Fe3GaTe2","authors":"","doi":"10.1016/j.physb.2024.416615","DOIUrl":"10.1016/j.physb.2024.416615","url":null,"abstract":"<div><div>Fe<sub>3</sub>GaTe<sub>2</sub>, with intrinsic magnetism at ambient temperature and high perpendicular magnetic anisotropy, is a promising van der Waals material for 2D-materials-based spintronic devices. Herein, we report the anisotropic magnetocaloric effects and magnetic critical phenomena in Fe<sub>3</sub>GaTe<sub>2</sub> single crystal. Owing to the large anisotropy, magnetic entropy change <span><math><mrow><mo>(</mo><mrow><mo>−</mo><mo>Δ</mo><msub><mi>S</mi><mi>M</mi></msub></mrow><mo>)</mo></mrow></math></span> shows anisotropic character with <span><math><mrow><mo>−</mo><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>max</mi></msubsup></mrow></math></span> of 1.67 J kg<sup>−1</sup> K<sup>−1</sup> along the <em>c</em> axis and 1.11 J kg<sup>−1</sup> K<sup>−1</sup> in the <em>ab</em> plane under field change of 5 T. The rotating <span><math><mrow><mo>Δ</mo><msub><mi>S</mi><mi>M</mi></msub></mrow></math></span> from the <em>ab</em> plane to the <em>c</em> axis reaches 0.67 J kg<sup>−1</sup> K<sup>−1</sup> at magnetic field of 5 T. By carefully fitting the <span><math><mrow><mo>−</mo><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>max</mi></msubsup></mrow></math></span> and relative cooling power (RCP), we determine their relationships to be <span><math><mrow><mo>−</mo><mo>Δ</mo><msubsup><mi>S</mi><mi>M</mi><mi>max</mi></msubsup><mo>∝</mo><msup><mi>H</mi><mi>n</mi></msup></mrow></math></span> (<em>n</em> = 0.694(1)) and <span><math><mrow><mi>R</mi><mi>C</mi><mi>P</mi><mo>∝</mo><msup><mi>H</mi><mi>m</mi></msup></mrow></math></span> (<em>m</em> = 1.301(3)) for the magnetic field along the <em>c</em>-axis. Further analysis of critical behavior near <em>T</em><sub><em>C</em></sub> reveals critical exponents <em>β</em> = 0.41(1) at <em>T</em><sub><em>C</em></sub> = 341.5(1) K, <em>γ</em> = 1.01(1) at <em>T</em><sub><em>C</em></sub> = 341.6(3) K, and <em>δ</em> = 3.67(15) at <em>T</em><sub><em>C</em></sub> = 340 K, indicating a three-dimensional complex magnetic exchange.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442317","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}
Pub Date : 2024-10-11DOI: 10.1016/j.physb.2024.416622
Mg-doped CdS samples were deposited via chemical bath deposition onto fluorine-doped tin oxide slides with varying levels of Mg-doping. Structural analysis revealed improved crystal quality in CdS films upon Mg incorporation. Morphological examinations indicated a reduction in grain size alongside appearance of smooth, void-free surfaces particularly evident at 3 % Mg-doping. Mg-doping also resulted in enhanced transparency of CdS films, notably at 3 % and 5 % within the visible spectrum. Efficient exciton dissociation was observed in hybrid solar cells based on 1 % and 3 % Mg-doped CdS, as evidenced by photoluminescence. Top-performing solar cell achieved an efficiency of 0.220 %, nearly seven times that of control device. 5 % Mg-doped CdS-based photodetectors exhibited favorable photosensing characteristics: a responsivity of 0.011 A/W, detectivity of 4.4 × 108 Jones, external quantum efficiency of 3.1 %, and rise/decay times of 26/25 ms at zero bias. These findings underscore beneficial effects of Mg-doping on both hybrid solar cell and self-driven photodetector performance.
{"title":"CBD-synthesized Mg-doped CdS thin films for hybrid solar cells and self-powered photodetectors","authors":"","doi":"10.1016/j.physb.2024.416622","DOIUrl":"10.1016/j.physb.2024.416622","url":null,"abstract":"<div><div>Mg-doped CdS samples were deposited via chemical bath deposition onto fluorine-doped tin oxide slides with varying levels of Mg-doping. Structural analysis revealed improved crystal quality in CdS films upon Mg incorporation. Morphological examinations indicated a reduction in grain size alongside appearance of smooth, void-free surfaces particularly evident at 3 % Mg-doping. Mg-doping also resulted in enhanced transparency of CdS films, notably at 3 % and 5 % within the visible spectrum. Efficient exciton dissociation was observed in hybrid solar cells based on 1 % and 3 % Mg-doped CdS, as evidenced by photoluminescence. Top-performing solar cell achieved an efficiency of 0.220 %, nearly seven times that of control device. 5 % Mg-doped CdS-based photodetectors exhibited favorable photosensing characteristics: a responsivity of 0.011 A/W, detectivity of 4.4 × 10<sup>8</sup> Jones, external quantum efficiency of 3.1 %, and rise/decay times of 26/25 ms at zero bias. These findings underscore beneficial effects of Mg-doping on both hybrid solar cell and self-driven photodetector performance.</div></div>","PeriodicalId":20116,"journal":{"name":"Physica B-condensed Matter","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433778","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}