Journal of Superconductivity and Novel Magnetism最新文献

{"title":"Synthesis and Study of Reactive Mesogen in a Spin Valve Structure","authors":"G. Manikandan,&nbsp;D. Dhanalakshmi,&nbsp;R. Devi,&nbsp;Ilari Angervo","doi":"10.1007/s10948-023-06602-8","DOIUrl":"10.1007/s10948-023-06602-8","url":null,"abstract":"<div><p>The hyperfine and spin–orbit coupling interaction are weak; due to these, organic materials are proposed to be excellent spin transport layer. In organic spin valve, reactive mesogen is used as the spacers, which have more advantages such as solution processing, higher mobility, and large area fabrication. The FeCo and NiFe dissimilar top ferromagnetic (FM) electrodes are used for spin injection and detection causing magneto resistance (MR) effect. The MR ratio was 3.2% at 50?K. Depending on various temperature, the MR behaviors were observed. This is the first reported spin MR effect in organic spin valve using reactive mesogen (RM) as a spacer layer. The results indicate that the HMPC (2,6-Bis 4-hydroxy propyloxy-3-methoxy benzaldehyde cyclohexanone) (RM) can be used as spin transport materials and provide clear for future organic based spintronics studies.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1511 - 1520"},"PeriodicalIF":1.8,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06602-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4032044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic Properties of Melt-Spun CoMnSi(B) Alloys","authors":"Rafael G. Suarez,&nbsp;Aida Miranda,&nbsp;J. L. Sánchez-Llamazares,&nbsp;I. Betancourt","doi":"10.1007/s10948-023-06597-2","DOIUrl":"10.1007/s10948-023-06597-2","url":null,"abstract":"<div><p>MnCoSi and MnCoSiB_0.5 alloys were obtained by melt-spinning technique in order to attain polycrystalline microstructures with average grain sizes well below 10 microns. Phase distribution studied by X-ray analysis indicated single-phase materials with orthorhombic structure and TiNiSi-type crystal symmetry. Chemical homogeneity was verified by means of scanning electron microscopy, whereas magnetic behavior corresponded to soft magnetic materials with coercivity values lower than 20 Oe and saturation magnetization of 80?emu/g. Magnetocaloric response of these MnCoSiB alloys was characterized by a maximum magnetic entropy change of 1.0?J/kg K (for a magnetic field variation of 2.0 Tesla) and attractive refrigerant capacity over 100?J/kg, which represents a significant enhancement respect to equivalent MnCoGe alloys.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1541 - 1547"},"PeriodicalIF":1.8,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06597-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5160429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, Magnetic and DC Electrical Resistivity Studies of Copper Substituted Mg0.6-xZn0.4CuxFe2O4 Ferrite System","authors":"S. Kuswanth Kumar,&nbsp;M. S. N. A. Prasad,&nbsp;A. Rama Krishna,&nbsp;B. Vikram Babu,&nbsp;B. Sathish Mohan,&nbsp;M. P. Rao,&nbsp;K. Samatha","doi":"10.1007/s10948-023-06590-9","DOIUrl":"10.1007/s10948-023-06590-9","url":null,"abstract":"<div><p>Ferrites made of copper substituted Mg_0.6-<i>x</i>Zn_0.4Cu_<i>x</i>Fe₂O₄ (<i>x</i> = 0.0, 0.1, 0.2 and 0.3) are extremely resistive and magnetic materials. They were produced using the ceramic method, and their structural, compositional, morphological, and functional characteristics were assessed using XRD, SEM, FT-IR, vibrating sample magnetometer (VSM), and dc electrical resistivity, respectively. They belong to the Fd-3m space group and have a spinel structure. After being calcined at 1000 °C, their particle size ranged from 1 to 1.56 μm. With the help of FT-IR analysis, which had absorption bands in the ranges of 570–576 cm^?1 and 424–430 cm^?1 for higher and lower frequency, respectively, their spinel structure was confirmed. The coercivity coefficient ranges from 73.33 to 154.7 Oe depending on the composition. The highest DC electrical resistivity was found to be 10⁶ Ω-cm at <i>x</i> = 0.1.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1571 - 1581"},"PeriodicalIF":1.8,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5121691","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}

{"title":"An Investigation of Superconducting Properties of Some Alkali Doped (A=Li, Na, K, Rb, Cs) Fe Based Superconductors – A First Principles Study","authors":"R. Mahesh,&nbsp;P. Venugopal Reddy","doi":"10.1007/s10948-023-06576-7","DOIUrl":"10.1007/s10948-023-06576-7","url":null,"abstract":"<div><p>The superconducting properties of alkaline doped Iron based superconductors (L=Li, Na, K, Rb, Cs) compounds were investigated using the ab-initio method. The studies were concentrated on investigatingthe electronic band structure, Fermi surface and superconducting properties of these materials. These compounds are having tetragonal structure (space group=129) with the P4/nmm. Plane wave calculations were performed by Wien2K code using the self-consistent method. To study the electronic structure and magnetic ordering, the Brich-Murnaghan equation was used. The estimated lattice parameters are comparable with the available experimental data. Density of states values at the Fermi level are found to increase continuously with increasing ionic radius of the dopent ion. The low value of electron phonon coupling constant may be attributedto increase in bond angle of A-Fe-A, Fe-A distances and degraded Fermi surface nesting. The absolute Fe magnetization of LiFeAs and NaFeAs are larger than other Alkali (A= K, Rb, Cs) compounds. Finally, the electron-phonon coupling constant (λ) values are found to decrease continuously</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 5","pages":"1353 - 1363"},"PeriodicalIF":1.8,"publicationDate":"2023-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06576-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5084671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Developing the Ferromagnetic Feature of ZnS:Cr Nanoparticles by Er Co-doping","authors":"B. Poornaprakash,&nbsp;Peddathimula Puneetha,&nbsp;S. Ramu,&nbsp;M. Siva Pratap Reddy,&nbsp;Sambasivam Sangaraju,&nbsp;P. Rosaiah,&nbsp;Adel El-marghany,&nbsp;Dong-Yeon Lee,&nbsp;Y. L. Kim","doi":"10.1007/s10948-023-06596-3","DOIUrl":"10.1007/s10948-023-06596-3","url":null,"abstract":"<div><h2>Abstract\u0000</h2><div><p>In the epoch of semiconductor technology, the design and development of doped semiconductor systems for spintronics and optoelectronics have allured hefty curiosity due to their modern physical characteristics. In this context, we report the chemical synthesis and tunable optical as well as magnetic properties of Zn_0.99-xEr_xCr_0.01S nanoparticles for the first time. Comprehensive structural studies proposed the effectual substitution of erbium and chromium ions into the parent matrix instead of Zn cation. A trivial spherical shaped cubic nanoparticle observed from the TEM micrographs. The erbium characteristic bands in the co-doped samples confirm the effectual incorporation of erbium co-doping in the ZnS matrix. The optical bandgap of the ZnS increased after chromium doing, and then, it decreased for erbium co-doping samples. The ferromagnetic feature of the ZnS:Cr nanoparticles significantly improved with respect to the Er co-doping concentration. The motto of the present investigation was to create the ferromagnetism in ZnS:Cr system and enrich that ferromagnetism via erbium co-doping. The plausible causes behind the enhanced ferromagnetism discussed in the results and discussion part.</p></div></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1595 - 1600"},"PeriodicalIF":1.8,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5482637","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}

{"title":"Estimation of Superconducting Critical-temperature of Molybdenum as a Function of Pressure","authors":"Bhaskar Khadka,&nbsp;Narayan Prasad Adhikari","doi":"10.1007/s10948-023-06598-1","DOIUrl":"10.1007/s10948-023-06598-1","url":null,"abstract":"<div><p>Recently, superconductors with high superconducting transition temperatures (<span>(T_{c})</span>) have been observed for their tuning abilities in <span>(T_{c})</span> due to application of ultra high pressure. In the present work, we considered 13 pressure values ranging from ambient (0 GPa) up to the very high pressure of 250 GPa. Electron–phonon coupling constant was estimated and entitled as the main parameter to study the effect of pressure on <span>(T_{c})</span> of molybdenum (Mo) under the density functional perturbation theory. The critical temperature of Mo at 0 GPa was estimated as 1.04 K, which agrees well with previous computational study. Mo element is then subjected to aforementioned range of pressure wherein <span>(T_c)</span> first decreased and then increased; this variation in <span>(T_c)</span> with pressure justified its tuning ability as well. <span>(T_{c})</span> is first decreased from 1.04 to 0.76 K for modest pressure range of 0–30 GPa and increased from 0.76 to 8.18 K for all other ranges of pressure from 30 to 250 GPa. This anomalous behavior of <span>(T_c)</span> is attributed to the irregular decrement and increment behavior of electron–phonon coupling constant and density of states at the Fermi level.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1503 - 1509"},"PeriodicalIF":1.8,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5052953","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}

{"title":"Structural, Magnetic, and Dielectric Properties for Mg0.6Co0.2Cu0.2FeCrO4 Spinel Ferrites Prepared Under Different Calcination Temperatures","authors":"Darine Harrabi,&nbsp;Sobhi Hcini,&nbsp;Jamila Dhahri,&nbsp;Nejeh Hamdaoui,&nbsp;Raihane Charguia,&nbsp;M. L. Bouazizi,&nbsp;S. Mansouri","doi":"10.1007/s10948-023-06591-8","DOIUrl":"10.1007/s10948-023-06591-8","url":null,"abstract":"<div><p>The calcination temperature effects on structural, magnetic, morphological, electrical, and dielectric properties for Mg_0.6Co_0.2Cu_0.2FeCrO₄ spinel ferrites have been investigated in this work. The samples (abbreviated as S900 and S1100) were prepared by the sol-gel route and calcined at two different temperatures (900?°C and 1100?°C). The thermogravimetric analysis was used to investigate the weight loss versus temperature and the formation of the spinel phases. The cation distributions were estimated for the samples using experimental XRD patterns based on the Rietveld refinement of the atomic occupancy values. With increasing calcination temperature, unit cell parameters and average crystallite size show an increasing trend. From the magnetic hysteresis loops, low coercive fields were obtained, making Mg_0.6Co_0.2Cu_0.2FeCrO₄ ferrites suitable candidates for soft magnetic devices. Nyquist-diagrams modeling shows that the conduction process in the samples is governed by the effect of grain and grain boundary contributions. Impedance and modulus curves show a dielectric relaxation phenomenon in the samples with non-Debye nature. The samples show electrical insulating (I)-semiconducting (S) transitions at <i>T</i>_<i>IS</i>?=?360?K for S900 and <i>T</i>_<i>IS</i>?=?400?K for S1100. Both NSPT and CBH models were used to explain the sample conduction process. Due to the increase in crystallite size with increasing calcination temperatures, activation energies decrease from 0.279 to 0.211?eV for S900 and S1100, respectively. In addition, the synthesized materials exhibit low dielectric constants and dielectric losses at higher frequencies as well as high electrical resistivity. These properties make Mg_0.6Co_0.2Cu_0.2FeCrO₄ samples suitable candidates for high-frequency applications and microwave absorption devices.\u0000</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1549 - 1569"},"PeriodicalIF":1.8,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06591-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5010444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrical Resistance of Hydrides Under High Pressure: Evidence of Superconductivity or Confirmation Bias?","authors":"J. E. Hirsch","doi":"10.1007/s10948-023-06594-5","DOIUrl":"10.1007/s10948-023-06594-5","url":null,"abstract":"<div><p>During the past 9 years, extensive experimental evidence has been presented that is claimed to demonstrate that hydrogen-rich materials under high pressure are high-temperature superconductors, as predicted by conventional BCS-electron–phonon theory. Foremost among the experimental evidence are electrical resistance measurements, which claimed to show that the resistivity of these materials falls well below that of the best normal metals within experimental accuracy. Here I propose an alternative explanation for the vanishingly small resistance reported for these materials that does not involve superconductivity.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1495 - 1501"},"PeriodicalIF":1.8,"publicationDate":"2023-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06594-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5127098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tunable Magnetic Phase Change and Polaronic Hopping Conductions in (Sm, Mn) Half Doped LaFeO3 Nanoparticle","authors":"S. Dash,&nbsp;T. Lakshmana Rao","doi":"10.1007/s10948-023-06595-4","DOIUrl":"10.1007/s10948-023-06595-4","url":null,"abstract":"<div><p>Effect of simultaneous Sm and Mn substitutions around half-doping level on the structural, magnetic and low temperature electronic behaviour of LaFeO₃ nanoparticle is extensively studied. The SXRD and FESEM data shows a single-phase nanoparticle of size 33?nm. A drastic magnetic phase change with a low temperature non-ergodic phase is seen compared to the parent LaFeO₃ (G-type antiferromagnetic) and this typical behaviour stems from the facts that, simultaneous presence of Sm and Mn alters the Fe crystal environment as well as its multiplicity which leads to improved exchange interactions among different ions. The doped nanoparticle shows a colossal dielectric response. Impedance, modulus spectra and ac conductivity analysis are used to find the conduction process involved in the system and it is related to the hopping conduction through grain and grain boundary resistances. The possibility of the polaronic part may arise from the interactions among mixed-valence state of Fe (Fe³⁺/Fe²⁺), Mn (Mn³⁺/Mn²⁺) and from the oxygen vacancies. Moreover, the ac-electrical conductivity is analysed using Jonscher’s double-power law and Jump relaxation model.\u0000</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 6","pages":"1521 - 1532"},"PeriodicalIF":1.8,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06595-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4795823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Column Defects on the Vortex Dynamics of Superconducting Thin Film with Ginzburg–Landau Parameters","authors":"Yufeng Zhao,&nbsp;Jiantang Xi","doi":"10.1007/s10948-023-06571-y","DOIUrl":"10.1007/s10948-023-06571-y","url":null,"abstract":"<div><h2>Abstract\u0000</h2><div><p>The time-dependent Ginzburg–Landau equations (TDGL) for a type-II superconducting film containing columnar defects are solved by the finite difference method. The effect of the number of defects on the flux dynamics inside the superconducting film is discussed. The effect of the Ginzburg–Landau parameter <span>(kappa)</span> on the vorticity of superconducting films with columnar defects is also analyzed. The results show that the formation of vortices is affected when the superconductor contains columnar defects. In addition, the defects and the Ginzburg–Landau parameter <span>(kappa)</span> also affect the maximum magnitude of the order parameter and the number of defects. Finally, we discuss the relationship between the magnetization of superconducting films with columnar defects and the external magnetic field.</p></div></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"36 5","pages":"1343 - 1352"},"PeriodicalIF":1.8,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-023-06571-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4794563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}