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•Orthorhombic Pr2FeMnO6 shows negative magnetization at low applied magnetic fields.•The interaction between two magnetic components leads to the negative magnetization.•The ...transition from ferromagnetic to paramagnetic phase is observed at Tc = 576 K.•Exchange bias observed below 200 K is due to magnetic exchange anisotropy.•Short range ferromagnetic correlation lead to Griffiths-like phase in Pr2FeMnO6.
The perovskite Pr2FeMnO6 has been synthesized by citrate-gel combustion method. The material has an orthorhombic crystal structure with Pbnm space group. The presence of Fe3+ and Mn3+ cations in the material are confirmed by XPS analysis. A magnetization sign reversal is observed for the material at low-temperatures in low applied magnetic fields. When the applied field or temperature is increased, the negative magnetization got diminished. Such a sign reversal of magnetization is observed for the material as a result of the interaction between components of paramagnetic Pr3+ and Mn3+ moments opposite to the component of the ferromagnetic Fe3+ moment or the anti-aligned Fe-rich regions to that of Mn-rich regions containing with Pr3+. Negative exchange bias is also exhibited by Pr2FeMnO6 below 200 K which can be ascribed to the Dzyaloshinskii-Moriya interaction and magnetic exchange anisotropy. A high-temperature magnetic transition at TC = 576 K is identified for the material from the thermomagnetic data. From the detailed analysis of the thermomagnetic data, the presence of ferromagnetic short-range correlations is observed far above the TC, which suggests a Griffiths-like phase with Griffiths temperature at TG = 681 K.
Monoclinic Sm2CuMnO6 is a fascinating material that exhibits intriguing magnetic and dielectric properties. In this study, we investigated the magnetic transition, conduction mechanism, and ...dielectric behavior of the material. Mott's variable range hopping of polarons is proposed as a satisfactory explanation for the conduction process, shedding light on the underlying charge transport mechanism. Furthermore, the material displays a spin glass transition at a freezing temperature of Tf = 18 K, suggesting the presence of competing magnetic interactions. Dielectric measurements reveal intriguing temperature and frequency dependence of the dielectric constant (ε) in Monoclinic Sm2CuMnO6. Below 100 K, the dielectric constant remains unchanged with variations in both temperature and frequency, indicating a stable dielectric response. However, above 100 K, ε exhibits an increasing trend with rising temperature and also displays frequency dependence. This behavior suggests the contribution of both deformational and relaxation polarizations, emphasizing the complex nature of the dielectric response.
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•Monoclinic Sm2CuMnO6 perovskite has been prepared by the Modified pechini method.•Variable range hopping of polarons constitutes the conduction mechanism.•Spin glass behavior observed due to the competing interaction present in the compound.•Maxwell-Wagnger effect and dipolar polarization constitutes the dielectric properties.
Nano-tungsten trioxide (WO 3 ) particles were introduced homogeneously into Bi 1.2 Pb 0.3 Sr 1.54 Ca 2.06 Cu 3 O y (Bi 2223) superconductor matrix by a sol-casting technique and their effect on flux ...pinning properties was studied. To prevent W substitution at a lattice site of the matrix phase, WO 3 nanoparticles were added to processed Bi 2223 powders, which helped to retain transition temperature ( T c ) near 105 K. The magnetic properties were obtained in the temperature ( T ) range of 10 to 77 K and up to 9 T magnetic fields ( B ). The temperature and field dependences of critical current densities ( J c ) and the flux pinning force densities ( F p ) were examined in terms of the possible sources of flux pinning in the samples. The addition of low concentrations (0.1 wt.%) of nano WO 3 led to effective pinning and enhancement of current densities to higher fields, up to 77 K, compared to Bi 2223. Analysis of F p (B) curves showed normal surface pinning at platelet/grain boundary defects to be dominant at low fields at all temperatures, while additional pinning from WO 3 is observed at higher fields. The limiting fields where pinning from different mechanisms vanishes are estimated using scaling laws. Irreversibility fields ( B irr ) estimated from the high field region of F p (B) curves suggest that substantial pinning is caused by nano WO 3 addition to Bi 2223.
One dimensional multiferroic systems with spin-charge coupling at room temperature are highly useful in future multifunctional devices. A facile protocol was used to process one dimensional ...multiferroic heterostructures of Ni–BaTiO 3 (Ni@BTO) by adopting the wet chemical reduction of hierarchical Ni nanowires, followed by controlled addition of barium titanate nanoparticles. The magnetic and electric properties of hierarchical Ni nanowires decorated with BaTiO 3 (BTO) nanoparticles suggest that their magnetic and electric transport mechanisms are influenced by ferroelectric BaTiO 3 coating. The surface between the prickles in the hierarchical Ni nanowires is visibly covered with BTO nanoparticles, forming a partial core–shell magnetoelectric system. In the typical Ni@BTO, improved coercivity was achieved and the magnetoelectric coupling coefficient of 517 μV cm −1 Oe −1 was obtained. Since ferromagnetic metals are conducting, Ni-based multiferroic composite structures were difficult to realize. Nevertheless, this is the first report on the encapsulation of nickel-based nanowires with barium titanate, where the former is synthesized without the aid of templates, external magnetic field, or pressure. Hence, the suggested protocol has the potential to develop leakage-free, tailor-made magnetoelectric nanostructures for memory applications.
One dimensional multiferroic systems with spin-charge coupling at room temperature are highly useful in future multifunctional devices. A facile protocol was used to process one dimensional ...multiferroic heterostructures of Ni-BaTiO
3
(Ni@BTO) by adopting the wet chemical reduction of hierarchical Ni nanowires, followed by controlled addition of barium titanate nanoparticles. The magnetic and electric properties of hierarchical Ni nanowires decorated with BaTiO
3
(BTO) nanoparticles suggest that their magnetic and electric transport mechanisms are influenced by ferroelectric BaTiO
3
coating. The surface between the prickles in the hierarchical Ni nanowires is visibly covered with BTO nanoparticles, forming a partial core-shell magnetoelectric system. In the typical Ni@BTO, improved coercivity was achieved and the magnetoelectric coupling coefficient of 517 μV cm
−1
Oe
−1
was obtained. Since ferromagnetic metals are conducting, Ni-based multiferroic composite structures were difficult to realize. Nevertheless, this is the first report on the encapsulation of nickel-based nanowires with barium titanate, where the former is synthesized without the aid of templates, external magnetic field, or pressure. Hence, the suggested protocol has the potential to develop leakage-free, tailor-made magnetoelectric nanostructures for memory applications.
One dimensional multiferroic systems with spin-charge coupling at room temperature are highly useful in future multifunctional devices.
•Y2CrMnO6 perovskite is prepared by modified Pechini-method.•The magnetic transition temperature of the material is found to be at 33 K.•Ferromagnetic short-range correlations are present in the ...compound lead to Griffiths-like phase.
Temperature-dependent magnetic measurements indicate a magnetic transition (TC) at 33 K in monoclinic Y2CrMnO6. The presence of different cations Cr 2+, Cr3+, Mn3+, and Mn4+ leads to incompatible magnetic interactions in the material. The Curie-Weiss (CW) fit of the magnetic susceptibility suggests that antiferromagnetic interactions are prominent in the material and the deviation of the susceptibility from the CW law near above the TC hints the presence of a Griffiths-like phase due to ferromagnetic short-range interactions up to the Griffiths temperature, TG = 98 K.
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•Sm2CrMnO6 have a monoclinic structure with P121/n1 space group with Tc = 50 K.•Sign reversal of magnetization observed in low applied magnetic fields.•The interaction between the ...anti-aligned components results in the sign reversal.
A sign reversal of magnetization is observed in Sm2CrMnO6 synthesized via the citrate-gel method. The material crystallizes in monoclinic crystal structure with P121/n1 space group. The presence of Cr3+ and Mn3+ cations is confirmed by X-ray photoelectron spectroscopy analysis. The transition temperature (TC) is found to be at 50 K from the thermomagnetic data. The magnetization reverses its sign below a particular temperature under field cooled condition and the effect is reduced and disappeared at higher applied magnetic fields. The combined interaction between different magnetic components due to the presence of Sm3+, Cr3+, and Mn3+ leads to the sign reversal of magnetization.
One dimensional multiferroic systems with spin-charge coupling at room temperature are highly useful in future multifunctional devices. A facile protocol was used to process one dimensional ...multiferroic heterostructures of Ni–BaTiO3 (Ni@BTO) by adopting the wet chemical reduction of hierarchical Ni nanowires, followed by controlled addition of barium titanate nanoparticles. The magnetic and electric properties of hierarchical Ni nanowires decorated with BaTiO3 (BTO) nanoparticles suggest that their magnetic and electric transport mechanisms are influenced by ferroelectric BaTiO3 coating. The surface between the prickles in the hierarchical Ni nanowires is visibly covered with BTO nanoparticles, forming a partial core–shell magnetoelectric system. In the typical Ni@BTO, improved coercivity was achieved and the magnetoelectric coupling coefficient of 517 μV cm−1 Oe−1 was obtained. Since ferromagnetic metals are conducting, Ni-based multiferroic composite structures were difficult to realize. Nevertheless, this is the first report on the encapsulation of nickel-based nanowires with barium titanate, where the former is synthesized without the aid of templates, external magnetic field, or pressure. Hence, the suggested protocol has the potential to develop leakage-free, tailor-made magnetoelectric nanostructures for memory applications.
Orthorhombic perovskite Pr2CrMnO6 has been synthesized by the Pechini method. XPS analysis confirms the presence of multiple oxidation states of Cr2+/Cr3+ and Mn3+/Mn4+ in the compound. From the ...electrical transport study, it is found that the resistivity of the material varies from 64 × 104–3 × 104 Ohm meter (Ωm) in the temperature range of 123–300 K. Variable range hopping of polarons is found to be responsible for the conduction in the material. The transition temperature (TC) of the compound is found to be at 57 K. From thermomagnetic data, the presence of short-range ferromagnetic correlations is confirmed, which constitutes the Griffiths-like phase in Pr2CrMnO6 up to the Griffiths temperature TG = 144 K.
