Coexistence of ferromagnetism and superconductivity in Pb/PbO core/shell nanoparticles

Hsu, Chien-Kang; Hsu, Daniel; Wu, Chun‐Ming; Li, Chi-Yen; Hung, Chi-Hang; Lee, Chi−Hung; Li, Wen-Hsien

doi:10.1063/1.3561766

Cited by 9 publications

(5 citation statements)

References 15 publications

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“…The use of borohydride reduction or polyol reactions provides some degree of shape control in nanoparticles of elemental superconductors [98]. Recently, colloidal synthesis has been employed to grow high quality monodispersed isolated Pb nanoparticles with a coreshell structure [99,100]. There are a number of reports on the growth of capped nanoparticles of superconductors such as MgB 2 , MgCNi 3 , Sn and Pb, showing ways to isolate individual particles from each other [101,102].…”

Section: Chemical Methodsmentioning

confidence: 99%

A review of finite size effects in quasi-zero dimensional superconductors

Bose

Ayyub

2014

Rep. Prog. Phys.

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Quantum confinement and surface effects (SEs) dramatically modify most solid state phenomena as one approaches the nanometer scale, and superconductivity is no exception. Though we may expect significant modifications from bulk superconducting properties when the system dimensions become smaller than the characteristic length scales for bulk superconductors-such as the coherence length or the penetration depth-it is now established that there is a third length scale which ultimately determines the critical size at which Cooper pairing is destroyed. In quasi-zero-dimensional (0D) superconductors (e.g. nanocrystalline materials, isolated or embedded nanoparticles), one may define a critical particle diameter below which the mean energy level spacing arising from quantum confinement becomes equal to the bulk superconducting energy gap. The so-called Anderson criterion provides a remarkably accurate estimate of the limiting size for the destabilization of superconductivity in nanosystems. This review of size effects in quasi-0D superconductors is organized as follows. A general summary of size effects in nanostructured superconductors (section 1) is followed by a brief overview of their synthesis (section 2) and characterization using a variety of techniques (section 3). Section 4 reviews the size-evolution of important superconducting parameters-the transition temperature, critical fields and critical current-as the Anderson limit is approached from above. We then discuss the effect of thermodynamic fluctuations (section 5), which become significant in confined systems. Improvements in fabrication methods and the increasing feasibility of addressing individual nanoparticles using scanning probe techniques have lately opened up new directions in the study of nanoscale superconductivity. Section 6 reviews both experimental and theoretical aspects of the recently discovered phenomena of 'parity effect' and 'shell effect' that lead to a strong, non-monotonic size dependence of the superconducting energy gap and associated properties. Finally, we discuss in section 7 the properties of ordered heterostructures (bilayers and multilayers of alternating superconducting and normal phases) and disordered heterostructures (nanocomposites consisting of superconducting and normal phases), which are primarily controlled by the proximity effect.

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Section: Chemical Methodsmentioning

confidence: 99%

A review of finite size effects in quasi-zero dimensional superconductors

Bose

Ayyub

2014

Rep. Prog. Phys.

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“…The neutron diffraction measurements in ferromagnetic superconductors ErRh 4 B 4 10 , HoMo 6 S 8 11 and HoMo 6 Se 8 12 indicate an inhomogeneous magnetic order coexisting with superconductivity. More recently, coexistence of these seemingly exclusive states was also seen in Pb/PbO core/shell nanoparticles 13 , and in two-dimensional interfaces between perovskite band insulators LaAlO 3 and SrTiO 3 14,15 .…”

Section: Introductionmentioning

confidence: 92%

Microscopic theory for a ferromagnetic nanowire/superconductor heterostructure: Transport, fluctuations, and topological superconductivity

Takei

Galitski

2012

Phys. Rev. B

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Motivated by the recent experiment of Wang et al. [Nature Physics 6, 389 (2010)], who observed a highly unusual transport behavior of ferromagnetic Cobalt nanowires proximity-coupled to superconducting electrodes, we study proximity effect and temperature-dependent transport in such a mesoscopic hybrid structure. It is assumed that the asymmetry in the tunneling barrier gives rise to the Rashba spin-orbit-coupling in the barrier that enables induced p-wave superconductivity in the ferromagnet to exist. We first develop a microscopic theory of Andreev scattering at the spin-orbit-coupled interface, derive a set of self-consistent boundary conditions, and find an expression for the p-wave mini-gap in terms of the microscopic parameters of the contact. Second, we study temperature-dependence of the resistance near the superconducting transition and find that it should generally feature a fluctuation-induced peak. The upturn in resistance is related to the suppression of the singleparticle density of states due to the formation of fluctuating pairs, whose tunneling is suppressed. In conclusion, we discuss this and related setups involving ferromagnetic nanowires in the context of one-dimensional topological superconductors. It is argued that to realize unpaired end Majorana modes, one does not necessarily need a half-metallic state, but a partial spin polarization may suffice. Finally, we propose yet another related class of material systems -ferromagnetic semiconductor wires coupled to ferromagnetic superconductors -where direct realization of Kitaev-Majorana model should be especially straightforward.

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“…25 Hsu et al reported superconducting Pb/PbO nanoparticles with a Pb core of 5 nm and a PbO layer of 1.2 nm. 26 Recently, a Pb/PbO compound confined in mesoporous carbon (OMC) was used as electrocatalysts for the electroreduction of CO 2 to CO. 27 Furthermore, reports on synthesizing nanocomposites of porous materials or zeolites with lead or lead oxides are limited. Dapurkar SE reported preparing and characterizing metal oxide nanoparticles, including PbO nanoparticles within the mesoporous channels of silicate molecular sieves MCM-41 and MCM-48.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Hsu et al. reported superconducting Pb/PbO nanoparticles with a Pb core of 5 nm and a PbO layer of 1.2 nm . Recently, a Pb/PbO compound confined in mesoporous carbon (OMC) was used as electrocatalysts for the electroreduction of CO 2 to CO …”

Section: Introductionmentioning

confidence: 99%

Pb/Pb₃O₄ Metal–Semiconductor Nanocomposite Obtained on 4A Zeolite─Optical and Structural Properties

Britto-Hurtado,

Larios-Rodriguez,

Ramírez-Bon

et al. 2024

ACS Omega

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This work describes a controlled and low-cost synthesis method to obtain Pb/Pb 3 O 4 nanocomposites using synthetic zeolite 4A. The nanostructures obtained have a core−shell configuration with 5−25 nm diameters. Highresolution transmission electron microscopy (HRTEM), BF, high-angle annular dark-field annular scanning transmission electron microscopy (HAADF-STEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and ultraviolet−visible (UV−vis) characterization techniques were used. Crystallographic planes ( 111), ( 200), and (220) for the core and planes ( 110) and ( 211) for the shell, corresponding to FCC and tetragonal structures for Pb and Pb 3 O 4 , respectively, were determined using HRTEM. The HAADF-STEM images allowed the analysis of intensity contrast images proportional to the number of atoms. XPS spectral analysis showed a 4.8 eV difference in binding energy between Pb 4f 7/2 and Pb 4f 5/2 for lead and lead oxide. EDS elemental mapping, XPS, and UV−vis spectroscopy analyses revealed the simultaneous presence of lead and lead oxide in the same structure. The band gap obtained for the shell was determined to be 4.50 eV. Consequently, Pb/Pb 3 O 4 nanocomposites show a higher response to highenergy photons, making them suitable for UV photocatalysis applications.

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Coexistence of ferromagnetism and superconductivity in Pb/PbO core/shell nanoparticles

Cited by 9 publications

References 15 publications

A review of finite size effects in quasi-zero dimensional superconductors

A review of finite size effects in quasi-zero dimensional superconductors

Microscopic theory for a ferromagnetic nanowire/superconductor heterostructure: Transport, fluctuations, and topological superconductivity

Pb/Pb₃O₄ Metal–Semiconductor Nanocomposite Obtained on 4A Zeolite─Optical and Structural Properties

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Coexistence of ferromagnetism and superconductivity in Pb/PbO core/shell nanoparticles

Cited by 9 publications

References 15 publications

A review of finite size effects in quasi-zero dimensional superconductors

A review of finite size effects in quasi-zero dimensional superconductors

Microscopic theory for a ferromagnetic nanowire/superconductor heterostructure: Transport, fluctuations, and topological superconductivity

Pb/Pb3O4 Metal–Semiconductor Nanocomposite Obtained on 4A Zeolite─Optical and Structural Properties

Contact Info

Product

Resources

About

Pb/Pb₃O₄ Metal–Semiconductor Nanocomposite Obtained on 4A Zeolite─Optical and Structural Properties