Magnetic properties of Co x Pt 100−x nanoparticles

Trung, Truong Thanh; Nhung, Do Thi; Van, Nguyen Thị Thanh; Nam, Nguyễn Hoàng; Luong, Nguyen Hoang

doi:10.1016/j.jsamd.2016.03.005

Cited by 3 publications

(4 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar loops are also obtained in direct micromagnetic simulations Kuźma et al (2022) and analytical theories Valdés et al (2021). Experimentally such M (H) loops are observed in elongated (shape anisotropy) and/or magneto-crystalline-anisotropic nanoparticles Trung et al (2016). However, only at low temperatures, below so-called blocking temperature Prozorov et al (1999) because above it a particle's magnetic moment can be easily flipped by thermal fluctuations, k B T Trung et al (2016).…”

Section: Magnetization Measurementssupporting

confidence: 69%

“…Experimentally such M (H) loops are observed in elongated (shape anisotropy) and/or magneto-crystalline-anisotropic nanoparticles Trung et al (2016). However, only at low temperatures, below so-called blocking temperature Prozorov et al (1999) because above it a particle's magnetic moment can be easily flipped by thermal fluctuations, k B T Trung et al (2016). (Indeed, in our case of large crystals thermal activation is not relevant in a large temperature interval.)…”

Section: Magnetization Measurementsmentioning

confidence: 76%

See 1 more Smart Citation

Study of the superconducting and magnetic properties of single crystals grown using the high-temperature solution method

View full text Add to dashboard Cite

The high-temperature solution growth method is a powerful tool for creating single crystalline samples that then enable the exploration of the superconductivity and magnetization of novel materials. This dissertation presents work that uses the solution growth method to synthesize CaK(Fe 1−x T x ) 4 As 4 and LaCrGe 3 single crystals. By measuring these single crystals, we study the relations or competition between superconductivity and magnetic transition, try to understand the unconventional superconductors, and explore the magnetic domain wall dynamics.Composition-transition temperature phase diagrams of CaK(Fe 1−x T x ) 4 As 4 , T = Cr and Mn, are constructed by elemental analysis, thermodynamic and transport measurements. As the substitution level increases, the superconducting transition temperature decreases monotonically and is finally suppressed below 1.8 K. Kink-like features appear in thermodynamic and transport measurements, which can be associated with antiferromagnetic transitions, and the transition temperature increases as the substitution level increases. Compared with electron-doped CaKFe 4 As 4 , the Cr and Mn phase diagrams are not overlapped as a function of hole doping, which indicates that the band-filling behavior is not the primary factor controlling the transition temperature in the Cr and Mn substitution samples. However, phase diagrams of Mn-and Cr-1144 are overlapped as a function of substitution level, x, which reveals the bi-modal responses of the phase diagram to transition metal substitution: on the side of Ni and Co substitution, the rigid band is observed with electron doping, and on the side of Mn and Cr substitution, compounds behave as ionic compounds and local moments substitution seems to be dominated instead of hole doping. Elastoresistivity coefficients, 2m 66 and m 11 − m 12 , as a function of temperature, are also measured in Mn substituted 1144. 2m 66 and m 11 − m 12 are qualitatively similar to CaK(Fe 1−x Ni x ) 4 As 4 . This may indicate that the magnetic order in Mn substituted system may xvi still be the same as CaK(Fe 1−x Ni x ) 4 As 4 . A clear change in H ′ c2 (T )/T c , coherence length, and the London penetration near the crossing of magnetic transition and superconducting transition as a function of substitution level is observed and probably is related to change of the Fermi surface due to magnetic order.LaCrGe 3 is an itinerant, metallic ferromagnet with a Curie temperature (T C ) of ∼ 86 K.Anisotropic M (H) isotherms, coupled with anisotropic AC susceptibility data is presented, and show a remarkable low-temperature coercivity associated with exceptionally sharp, complete magnetization reversals to and from fully polarized states. The behavior of coercivity is temperature dependent and was first discovered in bulk single crystalline samples, which may be due to very low bulk pinning, strong uniaxial anisotropy, and, possibly, strong surface pinning.

show abstract

Section: Magnetization Measurementssupporting

confidence: 69%

Section: Magnetization Measurementsmentioning

confidence: 76%

Study of the superconducting and magnetic properties of single crystals grown using the high-temperature solution method

View full text Add to dashboard Cite

show abstract

“…The preparation of Co−Pt NPs with alloy and core−shell structures is possible through the control of Co concentration using the proposed synthesis technique. Controlling of Pt ion and Co ion reduction timing by the Pt−OAm complex and the injection method via alcohol reduction, respectively, the designed synthesis of the Co−Pt core−shell nanoparticle, which possessed higher magnetic properties than any previous reports, [34][35][36][37][38]54 has been achieved. The formation of the core− shell structure is appreciable due to the following advantages: (a) the formation of a Co-rich core could lead to an increase in the magnetization compared to disordered Co−Pt alloy, and (b) the presence of Pt on the surface of the NPs could facilitate Au coating by reducing the lattice mismatch.…”

Section: Acs Applied Nano Materialsmentioning

confidence: 93%

“…Aiming to address the problems discussed above, we propose the use of a Co–Pt alloy as a magnetic core, which is more stable during synthesis and under oxidizing atmosphere than Fe and possesses reasonably high saturation magnetization (e.g., CoPt (Co 50 Pt 50 ) = 28 emu/g) . CoPt NPs have been already considered for magnetic recording and catalyst applications. − In most cases, CoPt NPs have been synthesized using the thermal decomposition technique, which lacked size, shape, and composition control. Here, the alcohol reduction method, which is a nonaqueous solution process using 1-octanol as the solvent, and the reducing agent are used for the synthesis of CoPt nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Magneto-Plasmonic Co@Pt@Au Nanocrystals for Biosensing and Therapeutics

Katagiri

Huaman

Matsumoto

et al. 2019

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

Multifunctional nanoparticles (NPs) exhibiting high magnetic property and plasmonic resonance are expected to be advanced nanomaterials which enable therapy, detection, and diagnosis simultaneously for medical applications. To achieve the practical performance of the multifunctional NPs, the precise design and synthesis are both required. In this work, considering the chemical stability and controllability, Co−Pt@Au core−shell NPs, which exhibit high magnetic property and plasmonic resonance, were theoretically designed based on calculation and then experimentally synthesized using an alcohol reduction method. Co−Pt NPs were uniformly synthesized using a technique which enables reduction control of Pt through the formation of a Pt−oleylamine complex. Moreover, depending on the Co/Pt ratio, the distribution of Co and Pt in a nanoparticle was precisely controlled, and as a result, Co−Pt alloy and Co@Pt core−shell NPs were individually prepared. In particular, Co@Pt NPs exhibit a high magnetic property and are suitable for Au coating due to a small lattice mismatch. In fact, Au coating onto Co@Pt NPs was successfully performed via inhomogeneous nucleation, which results in Co@Pt@Au NPs exhibiting plasmonic response of Au with high magnetic property and being dispersed in water by ligand exchange for in vivo use. The developed synthetic method enables designed synthesis of complicated multicomponent nanoparticles through tunable reduction reaction and provides highly potential NPs for transport and sensing applications.

show abstract

Unusual coercivity and zero-field stabilization of fully saturated magnetization in single crystals of LaCrGe3

Bud’ko

Prozorov

et al. 2023

Phys. Rev. B

View full text Add to dashboard Cite

Magnetic properties of Co x Pt 100−x nanoparticles

Cited by 3 publications

References 13 publications

Study of the superconducting and magnetic properties of single crystals grown using the high-temperature solution method

Study of the superconducting and magnetic properties of single crystals grown using the high-temperature solution method

Magneto-Plasmonic Co@Pt@Au Nanocrystals for Biosensing and Therapeutics

Unusual coercivity and zero-field stabilization of fully saturated magnetization in single crystals of LaCrGe3

Contact Info

Product

Resources

About