Journal of Superconductivity and Novel Magnetism最新文献

{"title":"Structural, Optical, and Magnetic Characteristics of (Zn0.5Ni0.5Fe2O4)0.5(Ba0.4Sr0.4Ca0.2Fe12O19)0.5 Nanocomposite Synthesized by the Ball-Milling Assisted Co-precipitation Route","authors":"Ahmad Najem, K. Habanjar, R. Awad, M. Matar","doi":"10.1007/s10948-024-06858-8","DOIUrl":"10.1007/s10948-024-06858-8","url":null,"abstract":"<div><p>In this study, the structural, optical, and magnetic properties of the Zn<sub>0.5</sub>Ni<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub> soft ferrite nanoparticle, the Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub> hard ferrite nanoparticle, and their nanocomposite (Zn<sub>0.5</sub>Ni<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub>)<sub>0.5</sub>(Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub>)<sub>0.5</sub> have been investigated. The nanoparticles and the nanocomposite were synthesized via co-precipitation and ball-milling routes, respectively. The formation, purity, and crystallinity of the samples were verified from the Rietveld analysis of X-ray diffraction (XRD) data as well as the essential absorption bands in the Fourier transform infrared (FTIR). The morphology and lattice spacing were investigated using transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). TEM micrographs visualized the hexagonal morphology of Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub> phase and the spherical-like shape of Zn<sub>0.5</sub>Ni<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub> phase. A scanning electron microscope (SEM) revealed well-distributed grains in the composite. Furthermore, energy-dispersive X-ray analysis (EDX) analysis validated the chemical compositions and the coexistence of Zn<sub>0.5</sub>Ni<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub> and Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub> phases in one matrix. Additionally, the optical behavior of the samples was tested via ultraviolet–visible and photoluminescence spectroscopies. Tauc plots were used to estimate the direct energy gap using UV spectroscopy. The direct and indirect energy band gaps of (Zn<sub>0.5</sub>Ni<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub>)<sub>0.5</sub>(Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub>)<sub>0.5</sub> nanocomposite are in between that of the pure phases, due to the increase in energy states with particle size. Also, near-band edge emissions and deep-level emissions have been observed in PL studies. X-ray photoelectric spectroscopy (XPS) studies were performed to investigate the elemental composition and cationic distribution. A good exchange coupling between both nanoparticles was verified via a single-phase behavior in the magnetic hysteresis loop. (Zn<sub>0.5</sub>Ni<sub>0.5</sub>Fe<sub>2</sub>O<sub>4</sub>)<sub>0.5</sub>(Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub>)<sub>0.5</sub> nanocomposite had a higher saturation magnetization (<span>({M}_{s})</span>) compared to Ba<sub>0.4</sub>Sr<sub>0.4</sub>Ca<sub>0.2</sub>Fe<sub>12</sub>O<sub>19</sub> phase and a squareness ratio (SQR) of 0.207 value (<span>(<0.5),)</span> making it suitable for use in magnetic hyperthermia, the production of permanent magnets, and extremely sensit","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889482","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":"Description of Resistive Transition for Type-II Superconductors","authors":"Denis Gokhfeld","doi":"10.1007/s10948-024-06894-4","DOIUrl":"10.1007/s10948-024-06894-4","url":null,"abstract":"<div><p>The Boltzmann sigmoid function effectively describes parameter changes during transitions between different states. A method using the Boltzmann function is proposed to analyze the temperature dependencies of superconductors near their critical temperature. Data for various superconductors (MgB₂, YBCO, Bi2212, a high-entropy alloy, CeH₉) are described, and parameters characterizing their resistive transition are estimated.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889608","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":"Tuning the Physical Properties of V-Ti-Ce Alloy Superconductors Through Successive Cold-Working and Annealing at 650 °C","authors":"Asi Khandelwal,&nbsp;Nida Mirza,&nbsp;L. S. Sharath Chandra,&nbsp;Rashmi Singh,&nbsp;Archna Sagdeo,&nbsp;M. K. Chattopadhyay","doi":"10.1007/s10948-024-06859-7","DOIUrl":"10.1007/s10948-024-06859-7","url":null,"abstract":"<div><p>V- Ti alloys are promising alternatives to Nb for the construction of superconducting solenoids that produce high magnetic fields. The critical current density (<span>(J_C)</span>), which quantifies the capacity of a superconductor to carry large dissipationless current, increases in the V-Ti alloys with the addition of Ce. Here, the effects of successive cold working and annealing on the electrical resistivity, <span>(J_C)</span>, and microstructure of the V<span>(_{0.59})</span>Ti<span>(_{0.40})</span>Ce<span>(_{0.01})</span> alloy are studied. The <span>(J_C)</span> is the maximum after the second cold rolling. Annealing at 650 <span>(^{circ })</span>C is found to nucleate and grow the <span>(alpha )</span>-phase which is detrimental to <span>(J_C)</span>, whereas the precipitation of the <span>(alpha ')</span>-phase is found to improve the <span>(J_C)</span>.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-024-06859-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142889705","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":"Relaxation of the Irreversible Magnetization in Proton-Irradiated MgB2","authors":"Viorel Sandu,&nbsp;Liviu Craciun,&nbsp;Ion Ivan,&nbsp;Alina Marinela Badea Ionescu,&nbsp;Rungtiwa Chidthong,&nbsp;Felicia Mihai,&nbsp;Gheorghe V. Aldica","doi":"10.1007/s10948-024-06877-5","DOIUrl":"10.1007/s10948-024-06877-5","url":null,"abstract":"<div><p>The paper presents the features of the magnetization decay of proton-irradiated MgB₂ bulk samples. Irradiation was performed with protons of energies between 8.6 and 15.07 MeV at different fluences. The creep activation energy is sensitive to the ratio between proton range and sample thickness. Experimental data show that the creep exponents are different from the theoretical predictions. When the proton range is shorter than the sample thickness (protons of 8.6 MeV), the thermomagnetic instabilities are strongly emphasized and affect the creep behavior.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875231","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":"Anti-site Disorder Driven Unusual Magnetic Properties in Sm( _{2} )NiMnO( _{6} ) Double Perovskite","authors":"S. Majumder,&nbsp;S. Saha,&nbsp;M. Tripathi,&nbsp;P. Rajput,&nbsp;S. N. Jha,&nbsp;R. J. Choudhary,&nbsp;D. M. Phase","doi":"10.1007/s10948-024-06845-z","DOIUrl":"10.1007/s10948-024-06845-z","url":null,"abstract":"<div><p>Cation ordered double perovskite RE<span>(_{2})</span>NiMnO<span>(_{6})</span> (RE: rare-earth) is commonly believed to show two distinct magnetic phase transitions, one at T = T<span>( _{C} )</span> because of Ni-O-Mn ferromagnetic (FM) super exchange interaction and another at T = T<span>( _{d} )</span> due to the polarization of RE spins opposite with respect to Ni-Mn network. In the present work, the structural, electronic, and magnetic properties of anti-site disordered Sm<span>( _{2} )</span>NiMnO<span>( _{6} )</span> (SNMO) have been investigated. It is observed that the presence of intrinsic B-site disorder results in an additional antiferromagnetic (AFM) coupling, mediated via Ni-O-Ni and Mn-O-Mn local bond pairs. As a consequence, the magnetic behavior of SNMO comprises of co-existing FM-AFM phases. Field-dependent inverted cusp-like trend in temperature-dependent magnetization, thermal irreversibility in cooling-warming paths of susceptibility, two-step reversibility in magnetic isotherm, and non-monotonicity in the thermal evolution of coercivity and remanence indicate the presence of competing magnetic phases over a wide range of temperature values (T<span>( _{d} &lt; )</span> T &lt; T<span>( _{C} )</span>).</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142870459","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":"The Influence of the Direction of Dislocation to the External Magnetic Field on the Critical Current Density and Strong Trapping of the Vortex Lattice in NbTi Wires","authors":"Daniel Gajda,&nbsp;Andrzej Zaleski","doi":"10.1007/s10948-024-06891-7","DOIUrl":"10.1007/s10948-024-06891-7","url":null,"abstract":"<div><p>Our results enable a better understanding and explanation of the physical phenomena associated with strong trapping of vortex lattice in superconducting wires. These measurements showed that dislocations oriented perpendicular to the external magnetic field most strongly trapped the vortex lattice in 8 T and much weaker in the 6 T magnetic field. Further research showed that dislocations situated in the angle of 45° to the external magnetic field most strongly trap the vortexes lattice in 7 T magnetic field. Subsequent results showed that dislocations oriented parallel to the external magnetic field trap the vortex lattice most strongly in the 6 T magnetic field and much weaker in the 8 T magnetic field. Previous studies have not reported these results and pinning analyses. Our results are also important for pinning centers created by irradiation for columnar defects.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142875193","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":"Magnetic Phase Diagram of Triangular Lattice Eu-Based Compound EuAg(_{4})Sb(_{2})","authors":"Shishi Ma,&nbsp;Changbo Zheng,&nbsp;Junbao He,&nbsp;Bo Liu,&nbsp;Sujuan Jin,&nbsp;Chaungchaung Ma,&nbsp;Hui Liang,&nbsp;Congbin Liu,&nbsp;Hao Shi","doi":"10.1007/s10948-024-06886-4","DOIUrl":"10.1007/s10948-024-06886-4","url":null,"abstract":"<div><p>We conducted a thorough study on the evolution of magnetic properties in the layered triangular lattice Eu-based antimonide EuAg<span>(_{4})</span>Sb<span>(_{2})</span>. The magnetic susceptibility measurements suggest that the title compound experiences two sequential antiferromagnetic transitions at approximately 10.8 K and 7.5 K, respectively, which is in contrast to the dominant ferromagnetic interactions indicated by a positive Curie-Weiss temperature in the paramagnetic region. This suggests the presence of a complex interaction between ferromagnetic and antiferromagnetic exchanges in EuAg<span>(_{4})</span>Sb<span>(_{2})</span>. The magnetic phase diagrams, constructed based on both magnetic susceptibility and isothermal magnetization measurements, provide unequivocal definitions for the various magnetic states observed in EuAg<span>(_{4})</span>Sb<span>(_{2})</span>. Remarkably, an intermediate transition state, accompanied by a 1/3 magnetization-plateau-like anomaly, emerges under in-plane magnetic fields, but missing under out-of-plane magnetic fields. Our result demonstrates that EuAg<span>(_{4})</span>Sb<span>(_{2})</span> hosts intriguing magnetic properties and could be a promising platform for exploring exotic magnetic properties of Eu<span>(^{2+})</span> triangular lattice compounds.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859607","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":"Magnetism and Critical Behavior of the Fullerene C18 Studied by Monte Carlo simulations","authors":"S. Idrissi,&nbsp;A. Jabar,&nbsp;L. Bahmad","doi":"10.1007/s10948-024-06838-y","DOIUrl":"10.1007/s10948-024-06838-y","url":null,"abstract":"<div><p>The Fullerene C18 is one of the most active types of nanostructures used as an active ingredient in several applications. This study used Monte Carlo simulations to investigate the magnetic properties of mixed 3/2 and 2 in the fullerene C18 systems. We first perform a theoretical analysis of the ground state phase diagrams. Indeed, we only present and analyze more stable configurations among all possible configurations. Second, calculations were performed to determine how the compound's magnetic properties changed when various physical parameters were altered. In addition, we provide studies of the magnetic behavior of the system at reduced temperature, reduced crystal fields, reduced exchange coupling interactions, and reduced external magnetic fields. Finally, we study and discuss the critical lowering temperature of fullerene C18. To conclude this study, we examined the different hysteresis loops when varying the values of the different physical parameters.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859671","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":"Detailed Analysis of the Superconducting Gap with Dynes Pair-Breaking Scattering","authors":"Anastasiya Lebedeva,&nbsp;František Herman","doi":"10.1007/s10948-024-06844-0","DOIUrl":"10.1007/s10948-024-06844-0","url":null,"abstract":"<div><p>We study the energy gap within the Dynes superconductor theory. This model generalizes the Bardeen-Cooper-Schrieffer (BCS) approach by including the pair-breaking scattering, introducing the tunneling in-gap states up to a Fermi level. We analytically solve the energy gap equation in various limit cases. The solution provides simple tools for further studies, compared to more complex numerics, and highlights the basic characteristics of the theory. First, in the critical limit of pair-breaking scattering, we derive an analytical form of zero-temperature gap to transition temperature ratio. Next, we derive the dependence of the energy gap close to critical temperature and look at its behavior for general and critical pair-breaking scattering rate. Furthermore, we compare our result with the numerical solution of the gap equation assuming general temperature. We show the range of temperatures, for which the analytical approximation is valid. In the end, we provide the approximative formula of the gap, assuming general pair-breaking scattering, emphasizing its exact behavior close to transition temperature.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10948-024-06844-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859549","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":"On the Lineshapes of Temperature-Dependent Transport Measurements of Superconductors Under Pressure","authors":"Alexander C. Mark,&nbsp;Russell J. Hemley","doi":"10.1007/s10948-024-06879-3","DOIUrl":"10.1007/s10948-024-06879-3","url":null,"abstract":"<div><p>Recent reports of superconductivity in the vicinity of room temperature have been the subject of discussion by the community. Specifically, features in the resistance-temperature (<i>R</i>-<i>T</i>) relations have raised questions. We show that many of these features can arise from previously unaccounted-for dynamic effects associated with the AC transport techniques often used in high-pressure experiments. These dynamic AC effects can cause the apparent resistance (<span>( R_{apparent} )</span>) to diverge from the DC resistance (<span>( R_{DC} )</span>), sharpen measured superconducting transitions, and produce other features in the measured <i>R</i>-<i>T</i> response. We also show that utilizing the full output of phase-sensitive transport measurements provides a valuable probe of superconducting samples in difficult-to-measure systems.</p></div>","PeriodicalId":669,"journal":{"name":"Journal of Superconductivity and Novel Magnetism","volume":"38 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844745","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}