scholarly journals Unravelling the nature of magneto-electric coupling in room temperature multiferroic particulate (PbFe0.5Nb0.5O3)–(Co0.6Zn0.4Fe1.7Mn0.3O4) composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Krishnamayee Bhoi ◽  
H. S. Mohanty ◽  
Ravikant ◽  
Md. F. Abdullah ◽  
Dhiren K. Pradhan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Room Temperature ◽  
Single Phase ◽  
Microstructural Analysis ◽  
Magnetic Ordering ◽  
Particulate Composite ◽  
Capacitance Measurement ◽  
Magnetic Field Sensors ◽  
Spintronic Devices ◽  
Electric Coupling

AbstractMultiferroic composites are promising candidates for magnetic field sensors, next-generation low power memory and spintronic devices, as they exhibit much higher magnetoelectric (ME) coupling and coupled ordering parameters compared to the single-phase multiferroics. Hence, the 3-0 type particulate multiferroic composites having general formula (1 − Φ)[PbFe0.5Nb0.5O3]-Φ[Co0.6Zn0.4Fe1.7Mn0.3O4] (Φ = 0.0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0, (1 − Φ) PFN-ΦCZFMO) were prepared using a hybrid synthesis technique. Preliminary structural and microstructural analysis were carried out using XRD and FESEM techniques, which suggest the formation of 3-0 type particulate composite without the presence of any impurity phases. The multiferroic behaviour of the composites is studied with polarization versus electric field (P-E) and magnetization versus magnetic field (M-H) characteristics at room temperature. The nature of ME coupling was investigated elaborately by employing the Landau free energy equation along with the magneto-capacitance measurement. This investigation suggests the existence of biquadratic nature of ME coupling (P2M2). The magneto-electric coupling measurement also suggests that strain mediated domain coupling between the ferroelectric and magnetic ordering is responsible for the magneto-electric behaviour. The obtained value of direct ME coefficient 26.78 mV/cm-Oe for Φ = 0.3, found to be higher than the well-known single-phase materials and polycrystalline composites.

Magnetoelectric Properties in Nickel Ferrite – Niobate Relaxor Bulk Composites

2012 ◽  
Vol 77 ◽  
pp. 215-219
Author(s):  
Piotr Guzdek
Keyword(s):  
Magnetic Field ◽  
Nickel Ferrite ◽  
Room Temperature ◽  
Single Phase ◽  
Magnetoelectric Effect ◽  
Multiferroic Materials ◽  
Fundamental Interest ◽  
Practical Applications ◽  
Magnetoelectric Properties ◽  
Properties Of Composites

Magnetoelectric effect in multiferroic materials is widely studied for its fundamental interest and practical applications. The magnetoelectric effect observed for single phase materials like Cr2O3, BiFeO3, Pb(Fe0.5Nb0.5)O3is usually small. A much larger effect can be obtained in composites consisting of magnetostrictive and piezoelectric phases. This paper investigates the magnetostrictive and magnetoelectric properties of nickel ferrite Ni0.3Zn0.62Cu0.08Fe2O4- relaxor Pb(Fe0.5Nb0.5)O3bulk composites. The magnetic properties of composites shows a dependence typical of such composite materials, i.e. it consists of a dominating signal from ferrimagnetic phase (ferrite) and a weak signal from paramagnetic (antiferromagnetic) phase (relaxors). Magnetoelectric effect at room temperature was investigated as a function of static magnetic field (300-7200 Oe) and frequency (10 Hz-10 kHz) of sinusoidal modulation magnetic field. The magnetoelectric effect increase slightly before reaching a maximum at HDC= 750 Oe and then decrease. The magnetoelectric coefficient increases continuously as frequency is raised, although this increase is less pronounced in the 1-10 kHz range.

scholarly journals The modified magnetodielectric response in KNN-CZFMO based particulate multiferroic composite system

2020 ◽  
Vol 10 (05) ◽  
pp. 2050024 ◽  
Author(s):  
Kulwinder Kaur ◽  
Mandeep Singh ◽  
Jaspal Singh ◽  
Sanjeev Kumar
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Room Temperature ◽  
Research Work ◽  
Hysteresis Loops ◽  
Magnetic Ordering ◽  
X Ray Diffraction ◽  
Universal Power Law ◽  
Multiferroic Composite ◽  
Magnetic Dielectric

Lead-free multiferroic composites of 1[Formula: see text](K[Formula: see text]Na[Formula: see text]NbO[Formula: see text](Co[Formula: see text]Zn[Formula: see text](Fe[Formula: see text]Mn[Formula: see text]O4 (KNN-CZFMO), where [Formula: see text]= 0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 1.0, have been investigated for their structural, morphological, electrical, magnetic, dielectric and magneto-dielectric properties. Presence of KNN and CZFMO crystal structure in each composite has been confirmed from X-ray diffraction analysis (XRD). Cuboidal-shaped grains of KNN and spherical-shaped grains of CZFMO have been observed by scanning electron microscopy (SEM). The room temperature ferroelectric behavior as confirmed by polarization versus electric field ([Formula: see text]–[Formula: see text] hysteresis loops has been found to be decreasing with increasing CZFMO concentration. Increasing magnetic ordering with the increase in CZFMO concentration in the prepared composites has been observed by magnetization versus magnetic field ([Formula: see text]–[Formula: see text] hysteresis loops. The electrical conductivity of composites has been studied using Jonscher’s universal power law. The room temperature dielectric constant ([Formula: see text] and dielectric loss (tan [Formula: see text] have been observed to decrease with the increase in the frequency of the applied external electric field. The dielectric relaxation behavior has been observed using curve fitting analysis via the Havriliak–Negami relaxation model. Maximum value of the magnetodielectric (MD) effect [Formula: see text]−11% at a frequency of 1 kHz with the applied magnetic field of 1 T has been achieved for 0.9 KNN−0.1 CZFMO ([Formula: see text]= 0.1) composite in the present research work.

scholarly journals Full voltage manipulation of the resistance of a magnetic tunnel junction

2019 ◽  
Vol 5 (12) ◽  
pp. eaay5141 ◽  
Author(s):  
Aitian Chen ◽  
Yuelei Zhao ◽  
Yan Wen ◽  
Long Pan ◽  
Peisen Li ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Efficient ◽  
Room Temperature ◽  
Efficient Solution ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Magnetic Tunnel Junction ◽  
Free Layer ◽  
Spintronic Devices ◽  
Electrical Control

One of the motivations for multiferroics research is to find an energy-efficient solution to spintronic applications, such as the solely electrical control of magnetic tunnel junctions. Here, we integrate spintronics and multiferroics by depositing MgO-based magnetic tunnel junctions on ferroelectric substrate. We fabricate two pairs of electrodes on the ferroelectric substrate to generate localized strain by applying voltage. This voltage-generated localized strain has the ability to modify the magnetic anisotropy of the free layer effectively. By sequentially applying voltages to these two pairs of electrodes, we successively and unidirectionally rotate the magnetization of the free layer in the magnetic tunnel junctions to complete reversible 180° magnetization switching. Thus, we accomplish a giant nonvolatile solely electrical switchable high/low resistance in magnetic tunnel junctions at room temperature without the aid of a magnetic field. Our results are important for exploring voltage control of magnetism and low-power spintronic devices.

Investigating the use of magnonic crystals as extremely sensitive magnetic field sensors at room temperature

2011 ◽  
Vol 98 (13) ◽  
pp. 132511 ◽  
Author(s):  
Mitsuteru Inoue ◽  
Alexander Baryshev ◽  
Hiroyuki Takagi ◽  
Pang Boey Lim ◽  
Kohei Hatafuku ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Room Temperature ◽  
Magnetic Field Sensors ◽  
Magnonic Crystals

Magnetic Field Sensors based on Magnetoresistance Effect in Organic Semiconductor Sandwich Devices

2005 ◽  
Vol 906 ◽  
Author(s):  
Govindarajan Veeraraghavan ◽  
Ömer Mermer ◽  
Yugang Sheng ◽  
Tho Duc Nguyen ◽  
Thomas Lee Francis ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Organic Semiconductor ◽  
Room Temperature ◽  
Experimental Characterization ◽  
Magnetoresistance Effect ◽  
Temperature Dependent ◽  
Magnetic Field Sensors ◽  
Mr Effect ◽  
Alternating Magnetic Fields

AbstractWe describe magnetic field sensors based on a recently discovered magnetoresistance (MR) effect in nonmagnetic organic semiconductor sandwich devices. The MR effect reaches up to 10% in a magnetic field of 10 mT at room temperature. We perform an extensive experimental characterization of this effect. We found that the MR effect is only weakly temperature dependent and does not depend on sign and direction of the applied magnetic field. We also measured the device response to alternating magnetic fields up to 100 kHz. To the best of our knowledge, the discovered MR effect is not adequately described by any of the MR mechanisms known to date.

scholarly journals Synthesis of bulk crystals and thin films of the ferromagnetic MnSb

2021 ◽  
Vol 23 (3) ◽  
pp. 387-395
Author(s):  
Muhammadyusuf Jaloliddinzoda ◽  
Sergey F. Marenkin ◽  
Alexey I. Ril’ ◽  
Mikhail G. Vasil’ev ◽  
Alexander D. Izotov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Curie Point ◽  
High Vacuum ◽  
Microstructural Analysis ◽  
Stoichiometric Composition ◽  
Deposition Process ◽  
Endothermic Effect ◽  
Magnetic Memory ◽  
Magnetic Field Sensors

High-temperature ferromagnets are widely used on a practical level. Based on them, magnetic memory for computers and various types of magnetic field sensors are created. Therefore, bulk ingots and thin-film samples of ferromagnet manganese antimonide (MnSb) with a high Curie point are of great interest, both from the practical and fundamental sides. Manganese antimonide films are obtained in hybrid structures using molecular-beam epitaxy. The thickness of the films does not exceed tens of nanometers. Despite their high sensitivity to magnetic fields, their small thickness prevents them from being used as magnetic field sensors. The aim of this work was to synthesise thick bulk ingots of manganese antimonide crystalsand films with a thickness of ~ 400 nm on sitall and silicon substrates. MnSb crystals were synthesised using the vacuum-ampoule method and identified using XRD, DTA, and microstructural analysis. The results of studies of bulk samples indicated the presence of an insignificant amount of antimony in additionto the MnSb phase. According to the DTA thermogram of the MnSb alloy, a small endothermic effect was observed at 572 °C, which corresponds to the melting of the eutectic on the part of antimony in the Mn-Sb system. Such composition, according to previous studies, guaranteed the production of manganese antimonide with the maximum Curie temperature. A study of the magnetic properties showed that the synthesised MnSb crystals were a soft ferromagnet with the Curie point ~ 587 K. Thin MnSb films were obtained by an original method using separate sequential deposition in a high vacuum of the Mnand Sb metals with their subsequent annealing. To optimise the process of obtaining films with stoichiometric composition, the dependences of the thickness of metal films on the parameters of the deposition process were calculated. The temperature range of annealing at which the metals interact with the formation of ferromagnetic MnSb films was established, the films were identified, and their electrical and magnetic properties were measured 

MÖSSBAUER STUDY OF Mg0.9Mn0.1CryFe2-yO4 SPINEL FERRITES

2006 ◽  
Vol 20 (07) ◽  
pp. 365-372 ◽  
Author(s):  
A. LAKSHMAN ◽  
P. S. V. SUBBA RAO ◽  
K. H. RAO
Keyword(s):  
Magnetic Field ◽  
Room Temperature ◽  
Single Phase ◽  
Field Model ◽  
Hyperfine Magnetic Field ◽  
Trivalent Chromium ◽  
X Ray Diffraction ◽  
Mössbauer Study ◽  
X Ray ◽  
Mössbauer Parameters

The effect of the substitution of paramagnetic trivalent chromium ions in stoichiometric magnesium–manganese ferrites has been studied with the composition Mg 0.9 Mn 0.1 Cr y Fe 2-y O 4 where y varies from 0.0, 0.1 to 0.9 in steps of 0.2. The single-phase cubic spinel structure of these samples has been confirmed from X-ray diffraction analyses. Mössbauer spectra of these samples studied at room temperature (300 K) showed two characteristic ferrimagnetic Zeeman sextets for lower concentration of Cr 3+ followed by relaxation phenomenon corresponding to y=0.9. The dependence of Mössbauer parameters, viz. isomer shift, quadrupole splitting, line width and hyperfine magnetic field on Cr 3+ concentration have been discussed. The variation of hyperfine magnetic field with increasing Cr 3+ content has been explained on the basis of Neel's molecular field model.

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