Showing papers on "Magnetocapacitance published in 2015"

Low magnetic field response single-phase multiferroics under high temperature

Abstract: A single-phase material where ferroelectricity and ferromagnetism coexist at room temperature (RT) is hardly available at present, and it is even more rare for such a material to further have an intrinsic and low magnetic field response magnetoelectric (ME) coupling at temperatures higher than RT. In this communication, a new single-phase Aurivillius compound, SrBi5Fe0.5Co0.5Ti4O18 has been discovered that exhibits a plausible intrinsic ME coupling. Remarkably, this property appears at a high temperature of 100 °C, surpassing all single-phase multiferroic materials currently under investigation. With a magnetocapacitance effect detectable at 100 °C and under a low response magnetic field, a RT functioning device was demonstrated to convert an external magnetic field variation directly into an electric voltage output. The availability of such a single-phase material with an intrinsic and low magnetic field response that is multiferroic at high temperature is important to the fundamental understanding of physics and to potential applications in sensing, memory devices, quantum control, etc.

The nature of magnetoelectric coupling in Pb(Zr,Ti)O3 -Pb(Fe,Ta)O3.

Abstract: The coupling between magnetization and polarization in a room temperature multiferroic (Pb(Zr,Ti)O3 -Pb(Fe,Ta)O3 ) is explored by monitoring the changes in capacitance that occur when a magnetic field is applied in each of three orthogonal directions. Magnetocapacitance effects, consistent with P(2) M(2) coupling, are strongest when fields are applied in the plane of the single crystal sheet investigated.

Interfacial Charge Induced Magnetoelectric Coupling at BiFeO3/BaTiO3 Bilayer Interface

Abstract: Bilayer thin films of BiFeO3–BaTiO3 at different thicknesses of BiFeO3 were prepared by RF-magnetron sputtering technique. A pure phase polycrystalline growth of thin films was confirmed from XRD results. Significantly improved ferroelectric polarization (2Pr ∼ 30 μC/cm2) and magnetic moment (Ms ∼ 33 emu/cc) were observed at room temperature. Effect of ferroelectric polarization on current conduction across the interface has been explored. Accumulation and depletion of charges at the bilayer interface were analyzed by current–voltage measurements which were further confirmed from hysteretic dynamic resistance and capacitance voltage profiles. Magnetoelectric coupling due to induced charges at grain boundaries of bilayer interface was further investigated by room temperature magnetocapacitance analysis. A room temperature magnetocapacitance was found to originate from induced charge at the bilayer interface which can be manipulated by varying the thickness of BFO to obtain higher ME coupling coefficient. D...

Multiferroic and magnetoelectric properties of CoFe2O4/Pb1−xSrxTiO3 composite films

Abstract: To realize multiferroic and magnetoelectric properties, bi-layered nanocomposite films consisting of CoFe2O4 (CFO)/Pb1−xSrxTiO3 (PST) phases (x = 0.1, 0.2, and 0.3) have been deposited on Pt/TiO2/SiO2/Si substrate by using a metallo-organic decomposition process. Both the PST perovskite and the CFO spinel phases are confirmed from X-ray diffraction patterns and Raman spectra of the composite films. The composite films exhibit room temperature multiferroic properties. The values of saturation magnetization (Ms), remanent magnetization (Mr), and coercive field (Hc) of the composite films are in the range of 108–119 kA/m, 42–51 kA/m, and 44.5–64.1 kA/m, respectively. In addition, the saturation polarization (Ps), remanent polarization (Pr), and electrical coercive field (Ec) are observed in the range of 11.3–14.4 μC/cm2, 2.9–4.8 μC/cm2, and 56–59.5 kV/cm, respectively. The dielectric response in the presence of applied magnetic field, Hdc ∼ 238.6 kA/m shows a high magnetocapacitance value ∼385% at frequency ...

Structural, dielectric, ferroelectric and magnetic properties of (x) CoFe 2 O 4 -(1-x) BaTiO 3 composite

Abstract: Composites of (x) CoFe2>/sub>O4-(1-x) BaTiO3 (for x = 0, 0.30, 0.40, 0.50) synthesized via solid state reaction method are reported. Structural analysis was carried out by X-ray diffraction analysis which confirms the formation of the hybrid composites with spinel phase and tetragonal phase. FESEM micrographs show closely packed microstructure with grain sizes varying in the range of 480 nm- 680 nm. Variation of dielectric constant with temperature at three fixed frequencies (1 kHz, 50 kHz and 100 kHz) was studied and it was found that the value of dielectric constant increases with an increase in the ferrite content. In ferroelectric study the values of coercive field (2Ec) increased with increasing ferrite content. The magnetic properties such as saturation magnetization (Ms) and magnetic moment (μB) calculated from the magnetic hysteresis loops are found to increase with an increase in ferrite content. The magnetoelectric effect of ferroelectric/ferrite composites was studied using magnetocapacitance which gives maximum value for 50 mol% addition of ferrite.

Sensitivity and Noise Evaluation of a Bonded Magneto(elasto) Electric Laminated Sensor Based on In-Plane Magnetocapacitance Effect for Quasi-Static Magnetic Field Sensing

Abstract: The quasi-static magnetic field detection of a layer-bonded magneto(elasto) electric (ME) laminate has been investigated by measuring the in-plane electric capacitance via its interdigital electrodes close to the piezoelectric resonant frequency. The ME-layered composite is considered as a stress-induced dielectric effect because there is practically no direct response of the electric capacitance to an external magnetic field. The sensitivity is dominated by the magnetoelastic coupling in the magnetic layer and on the stress induced by the permittivity change in the piezoelectric layer. The low-frequency magnetocapacitance effect is sensitive to an external magnetic bias which can modulate the electric permittivity by producing a stress. The magnetoelastic coupling is another important parameter for this magnetic field detection mode. For a given magnetic field, the amplitude of the magnetostriction is directly related to this parameter as well. Therefore, an optimal magnetic bias can maximize the induced strain or stress which is coupled into the piezoelectric layer through the change of the electric permittivity in this layer. To evaluate the sensitivity and the noise performance by the magnetocapacitance effect, we have used the piezoelectric and magnetic constitutive equations to predict the permittivity dependence. Experimentally, this sensor achieved an equivalent magnetic noise spectral density, presently still limited, by the noise of the detection electronics, $\sim 100$ pT/ $\surd $ Hz at 1 Hz and offered a dc detection capability. With the model and experimental nonlinear factors, an equivalent sensor noise spectral density close to the pT/ $\surd $ Hz can be ultimately predicted considering the mechanical loss limitation of the sensor.

Magnetopiezoelectric effect and magnetocapacitance in SmFe 3 ( BO 3 ) 4

Abstract: A giant magnetopiezoelectric effect has been revealed in samarium ferroborate. The effective piezomodulus is increased more than twice in the antiferromagnetic phase and it is reduced by a high magnetic field. The nature of the effect is in the joint contribution of both magnetoelectric and magnetoelastic interactions. The evolu-tion of this contribution in the magnetic field is caused by the growth of the magnetic energy including the spin reorientation. Additional data concerning the behavior of the high-frequency magnetocapacitance have been obtained. The parameters of magnetoelectric and magnetoelastic couplings and the magnetic anisotropy constant in the basal plane have been determined.

Structural, transport, magnetic and magnetoelectric properties of CaMn1−xFexO3−δ (0.0 ≤ x ≤ 0.4)

Abstract: The structural, magnetic, transport and magnetoelectric properties of parent and Fe doped CaMn1−xFexO3−δ (0.0 ≤ x ≤ 0.4) manganites are investigated using synchrotron X-ray, Raman, SQUID and nova control impedance analyzer. The Fe doped composition x = 0.3 shows a strong Maxwell–Wagner effect, and quite high positive magnetocapacitance (MC) of ∼ 8.45% at room temperature and at low magnetic field 7.8 kG has been observed. Rietveld refinement of synchrotron X-ray diffraction patterns suggests (i) a structural transformation from orthorhombic to cubic crystal system and (ii) an increase in lattice parameters with the substitution of Fe at the Mn site. Sintering at 1300 °C stabilizes the doping of higher ionic radii Fe+3 (0.645 A)/Fe+4 (0.585 A) atoms at the Mn+4 (0.53 A) site in CaMn1−xFexO3−δ. The Magnetization data show a transformation of the G type of antiferromagnetic arrangement of Mn+4 electrons spins in CaMnO3 into a paramagnetic spin type arrangement with Fe substitution. The AC conductivity of the Fe doped compositions decreases more than two orders of magnitude in comparison to CaMnO3−δ.

Large magnetocapacitance effect in magnetic tunnel junctions based on Debye-Fröhlich model

Abstract: The frequency dependence of tunneling magnetocapacitance (TMC) in magnetic tunnel junctions (MTJs) is investigated theoretically and experimentally. According to the calculation based on Debye-Frohlich model combined with Julliere formula, the TMC ratio strongly depends on the frequency and it has the maximum peak at a specific frequency. The calculated frequency dependence of TMC is in good agreement with the experimental results obtained in MgO-based MTJs with a tunneling magnetoresistance (TMR) ratio of 108%, which exhibit a large TMC ratio of 155% at room temperature. This calculation also predicts that the TMC ratio can be as large as about 1000% for a spin polarization of 87%, while the TMR ratio is 623% for the same spin polarization. These theoretical and experimental findings provide a deeper understanding on AC spin-dependent transport in the MTJs and will open up wider opportunities for device applications, such as highly sensitive magnetic sensors and impedance-tunable devices.

Room temperature magnetodielectric studies on Mn-doped LaGaO3

Abstract: Polycrystalline samples of LaGa1−xMnxO3 (0 ≤ x ≤ 0.3) were prepared by the solid-state reaction route. The phase purity of these samples was confirmed by powder x-ray diffraction experiments carried out on BL-12 at the Indus-2 synchrotron radiation source. The sample with x = 0.2 shows significant change in the value of capacitance with the application of a magnetic field. The observed results were understood by systematically analyzing magnetocapacitance (MC), magnetoresistance (MR), and dielectric loss as a function of frequency. Our results and analysis suggest that the observed magnetodielectric (MD) coupling may be due to the MR effect of the Maxwell–Wagner type and/or field-induced dipolar relaxation. Further, it is observed that oxygen stoichiometry plays a very crucial role in the observed MD coupling.

Enhanced magneto-capacitance response in BaTiO3–ferrite composite systems

Abstract: This research work focuses on the enhanced magneto-capacitance response in the composites of (1 − X)BaTiO3 : X(CoFe2O4/ZnFe2O4/Co0.5Zn0.5Fe2O4) (where X = 20, 30 and 40 wt%), prepared via a conventional solid-state mixing route using auto-combustion derived powders. A new observation is the existence of two different types of morphologies such as plate-like (size was ∼5 μm with a thickness ∼1 μm) and fine agglomerated nearly spherical shape of tetragonal BaTiO3 along with the polyhedral morphology (size of ∼0.5 to ∼2.5 μm) of cubic ferrites in the prepared composite systems. Unidirectional or random orientation of the plate-like morphology of BaTiO3 in these composite systems depends on the percentage of ferrite phase. In addition to the morphology effect, the magnetoresistance effect was analyzed using magneto-impedance study as a function of frequency as well as by Cole–Cole plots. The magnetoresistance effect was found to be dependent on the type and percentage of ferrites. The combined effects of phase morphology along with magnetoresistance and/or magnetostriction led to enhanced magneto-capacitance response in these composites. The percentage of magnetocapacitance values were found to be in the range between −3 to −9, −0.5 to −7 and +1.5 to −1.5 for BaTiO3 : CoFe2O4, BaTiO3 : ZnFe2O4 and BaTiO3 : Co0.5Zn0.5Fe2O4 composites, respectively, depending on the percentage of ferrite phase.

Possible coexistence of cycloidal phases, magnetic field reversal of polarization, and memory effect in multiferroic R0.5Dy0.5MnO3 (R = Eu and Gd)

Abstract: We report the occurrence of both ab and bc cycloidal ordering of Mn-spins at different temperatures and their possible coexistence at low temperatures in the polycrystalline mixed rare-earth compounds, R0.5Dy0.5MnO3 (R = Eu and Gd), which exhibit extraordinary magnetoelectric properties. While the polarization of Gd0.5Dy0.5MnO3 is comparable to TbMnO3, the compound Eu0.5Dy0.5MnO3 shows high value of polarization. However, both of them show giant magnetic tunability and exhibit large magnetocapacitance whose sign changes across the two cycloidal ordering temperatures. Intriguingly, the electric polarization can be reversed upon ramping up or ramping down the magnetic field, which has not been observed for any of the RMnO3 system. Most strikingly, these compounds show non-volatile ferroelectric memory effect even in the paraelectric and paramagnetic region (TC ≤ T ≤ 80 K). We attribute these remarkable properties to the coexistence of ab and bc cycloidal ordered phases.

Origin of magnetocapacitance in chemically homogeneous and inhomogeneous ferrites.

Abstract: The present work mainly focuses on the magnetodielectric (MD) effect in polycrystalline Ni0.9−yCuyZn0.1Fe1.98O3.97 (y = 0, 0.1, 0.2, 0.3, 0.4, 0.5) ferrite synthesized by a solid-state reaction method. Sintered samples showed the formation of CuO-rich grain boundary segregation for y ≥ 0.2. The appearance of segregation made the present material chemically inhomogeneous and electrically heterogeneous. A negative MD response was observed in homogeneous ferrite for y = 0 and 0.1 due to lattice distortion (an intrinsic effect), whereas a positive MD response occurs in chemically inhomogeneous segregated ferrite (y ≥ 0.2) due the collective effects of Maxwell–Wagner (MW) polarization with intrinsic magnetoresistance (an extrinsic effect).

Probing Spin Accumulation induced Magnetocapacitance in a Single Electron Transistor.

Abstract: The interplay between spin and charge in solids is currently among the most discussed topics in condensed matter physics Such interplay gives rise to magneto-electric coupling, which in the case of solids was named magneto-electric effect, as predicted by Curie on the basis of symmetry considerations This effect enables the manipulation of magnetization using electrical field or, conversely, the manipulation of electrical polarization by magnetic field The latter is known as the magnetocapacitance effect Here, we show that non-equilibrium spin accumulation can induce tunnel magnetocapacitance through the formation of a tiny charge dipole This dipole can effectively give rise to an additional serial capacitance, which represents an extra charging energy that the tunneling electrons would encounter In the sequential tunneling regime, this extra energy can be understood as the energy required for a single spin to flip A ferromagnetic single-electron-transistor with tunable magnetic configuration is utilized to demonstrate the proposed mechanism It is found that the extra threshold energy is experienced only by electrons entering the islands, bringing about asymmetry in the measured Coulomb diamond This asymmetry is an unambiguous evidence of spin accumulation induced tunnel magnetocapacitance, and the measured magnetocapacitance value is as high as 40%

Rapid preparation and magnetodielectric properties of trirutile Cr2WO6

Abstract: Dense pellets of > 99% purity trirutile Cr2WO6 were prepared in one step from starting oxides using spark plasma sintering, leading to simultaneous reaction and consolidation in 3 min at 1473 K. The reducing environment during processing may be partly responsible for the rapid reaction time in these oxides, with partial reduction of Cr3+ and the associated oxygen vacancies allowing rapid diffusion of cations. The low-temperature physical properties of Cr2WO6 were examined, and a new transition at T = 5.9 K was observed as an anomaly in the temperature-dependent dielectric permittivity and a corresponding anomaly in the specific heat. A strong enhancement of the magnetocapacitance is observed below this transition temperature at T = 5.9 K and may be associated with a change from collinear spin order to more complex spin order.

Structural, Dielectric, Magnetic And Magnetoelectric Characterization Of Co0.5Ni0.5Fe2O4 - Bi0.9La0.1FeO3 Composite

Abstract: Mixed spinel -perovskite composites of (x) Co0.5Ni0.5Fe2O4-(1−x) Bi0.9La0.1FeO3(x = 0, 0.25, 0.40, 0.55, 1.0) have been synthesized by conventional solid state reaction method and annealed at 850 oC. The X-ray diffraction (XRD) pattern shows that the composites consisted of spinel Co0.5Ni0.5Fe2O4 and rhombohedral perovskite Bi0.9La0.1FeO3 ceramics. FESEM micrographs show closely packed microstructure with grain size in the range 503 nm - 960 nm. Variation of dielectric constant and dielectric loss with temperature at two fixed frequencies (500 kHz and 1 MHz) was studied. The composite with composition x = 0.55/sintered at 850 oC exhibits the largest coercitivity (Hc) of 883 Oe. The saturation magnetization (Ms) and magnetic moment (µB) increase with an increase of Co0.5Ni0.5Fe2O4 concentration in the composites. From ferroelectric hysteresis loop analysis the values of remnant polarization (Pr) and coercive field (Ec) was found to lie in the range of 0.0180.745 µC/cm 2 and 3.89-6.06 kV/cm. The relative change of magnetocapacitance was found to be 6.6% at a magnetic field of 8 kOe for x = 0.55 composition. Impedance analysis suggests the presence of a temperature dependent electrical relaxation in the material having a typical negative temperature coefficient of the resistance (NTCR) behavior analogous to a semiconductor. Copyright © 2015 VBRI Press.

Temperature dependence of magnetization, anisotropy and hyperfine fields of NiFe 2−x Yb x O 4 (x = 0, 0.05, 0.075)

Abstract: Nickel ferrite (NiFe 2 O 4 ), an inverse spinel in which the tetrahedral (A) sites are occupied by Fe3+ ions and the octahedral (B) sites are occupied by Fe3+ and Ni2+ ions, can be represented as Fe A 3+ Ni B 2+ Fe B 3+ O 4 2− [1-3]. The cation distribution and the resulting magnetic properties are reported to be quite interesting in rare-earth doped nickel ferrite due to the absence of center of symmetry [2, 3]. Kamala Bharathi et al. have reported that, substitution of Fe3+ by Dy3+ ion in NiFe 2 O 4 causes development of magnetocapacitance, leads to ferroelectricity and affects several other properties [3]. These materials play an important role in applications (spintronic memory cell, high frequency devices etc) [4]. There are no reports on thermal behavior of magnetic anisotropy in the rare earth substituted Ni ferrites. Understanding these behaviors will be useful in novel applications such as heat-assisted magnetic recording [4, 5]. In the present work, the temperature dependence of magnetic anisotropy and hyperfine fields of NiFe 2−x Yb x O 4 (x = 0, 0.05, 0.075) are reported. All the samples were prepared by solid state reaction. The materials are found to have formed in inverse spinel structure, from the powder XRD patterns. Rietveld refinement carried out on the XRD patterns revealed that Yb3+ ions occupy the B site and the lattice is found to be expanded with the introduction of Yb3+. The lattice constants are 8.3415(1) A (reported value is 8.34 A [1]), 8.3436(0) A and 8.3463(5) A for x = 0, 0.05 and 0.075 compounds respectively. Magnetization was measured at 5 K, 100 K, 200 K, and 300 K and the magnetization was observed to decrease with x. This is attributed to substitution of Fe3+ by Yb3+ in the B-site. The saturation magnetization values, at all the measured temperatures obtained through Honda plots are given in Table 1. The moments calculated using Hund's rule (assuming that Yb3+ and Fe3+ moments are parallel) are 2.82 μ B /f.u., 2.76 μ B /f.u. and 2.71 μ B /f.u. for x = 0, 0.05 and 0.075 compounds respectively. The experimental values are less in comparison with the calculated moments. In NiFe 2 O 4 , this difference is in accordance with the reported literature [1-3]. At each temperature, M-H data were fitted to the law of approach to saturation (LAS) [1, 6] and K1(T), the first order magnetocrystalline anisotropy constant at a temperature T, was obtained from LAS. At any given temperature, the observed increase in K1 of x = 0.05 and 0.075 compared with x = 0, is explained on the basis of single-ion model i.e. localized divalent ions in the octahedral site. The temperature dependence of K1 of cubic systems was investigated by plotting ln K1(T) vs ln M(T). The slopes of the straight line obtained are 7.5, 12.5 and 11.44 for x = 0, 0.05 and 0.075 respectively. This can be compared with the value of 10 proposed for magnetic anisotropy in cubic systems [1, 6]. The deviation of the exponent is explained on the extent of localization of the divalent ion.

Magnetocapacitance effects in MnZn ferrites

Abstract: The magnetocapacitance effects of MnZn ferrites with different initial permeabilities have been studied systematically. Both intrinsic effect associated with magnetoelectric coupling and extrinsic effect, which means the combined contribution of magnetoresistance and the Maxwell-Wagner effect, have been observed simultaneously. Analysis shows that the relationship between the origins of both is in competitive equilibrium. Either of both mechanisms plays a dominant role in magnetocapacitance effects under different conditions, respectively, such as permeability and frequency of applied signals.

Enhancement of the magnetocapacitance effect in an external electric field in La x Bi 1- x FeO 3 films

Abstract: The goal of the study is to determine the value of magnetocapacitance under the substitution of lanthanum for bismuth in thin La x Bi1-x FeO3 films and to find out the effect of an external bias electric field on the magnetocapacitance effect. To solve this task, the dielectric permittivity, the magnetic permeability, and the loss tangent are measured in La x Bi1-x FeO3 films in magnetic fields of up to 8 kOe in the range of temperatures 100 K < T < 1000 K. Maxima of the permittivity and permeability at low temperatures and the dependence of the permeability on the prehistory of a sample are found. An increase in the magnetocapacitance due to the substitution of lanthanum for bismuth is observed. A giant enhancement of magnetocapacitance in an external electric bias field is revealed. These phenomena are attributed to the rearrangement of the domain structure.

Capacitive type magnetoimpedance effect in piezoelectric-magnetostrictive composite resonator

Abstract: In this article, a significant capacitive type magnetoimpedance effect of piezoelectric-magnetostrictive (PM) composite resonator is presented at room temperature. The variations of relatively effective permittivity of the PM resonator with a dc magnetic field are responsible for the capacitive type magnetoimpedance effect. About 225% and 50% of magnetoimpedance have been achieved at anti-resonance and resonance frequencies of the PM resonator, respectively, which reveals a stronger magnetoelectric coupling at the anti-resonance frequency than that at the resonance frequency of the PM resonator. A detailed analysis also indicates that the magnetocapacitance and magnetoinduction effects of the resonator were originated from the variations of relatively effective permittivity of the resonator. More than 200% and 170% of magnetocapacitance and magnetoinduction were achieved at room temperature in the anti-resonance window, respectively, and also about 150% and 60% of capacitance and induction modulation were observed in the resonance window by applying the dc magnetic fields. The capacitive type magnetoimpedance effect is expected to be used in the design of magnetic-field-tuned ultrasonic transducer.

Clarification of the magnetocapacitance mechanism for Fe 3 O 4 -PDMS nanocomposites

Abstract: We mainly focused on the magnetocapacitance effect of Fe3O4-PDMS nanocomposites. We also proposed the preparation method and measured microstructures, magnetic properties, and magnetocapacitance value of the nanocomposites. The magnetocapacitance measurement results show that the nanocomposites have magnetocapacitance property, the magnetocapacitance with magnetic field depends on the magnetic property, and the value at the same magnetic field is increasing with the volume fraction of Fe3O4 nanoparticles.The magnetocapacitance model is proposed to explain this phenomenon by analyzing the magnetic interaction between particles and the viscoelasticity of PDMS. We also calculated the theoretical capacitance value of all samples using the magnetization of nanoparticles and mechanical parameters of PDMS. From the theoretical values, it is concluded that the model we proposed can well explain the magnetocapacitance effect of Fe3O4-PDMS nanocomposites.

Anisotropic magnetocapacitance in ferromagnetic-plate capacitors

Abstract: The paper reports the observation of an anisotropic capacitance in a parallel plate $p$-$n$ junction capacitor where one plate is a ferromagnetic semiconductor, GaMnAs, and the other is nonmagnetic $n$-doped GaAs. The capacitance depends on the angle of the magnetization of the ferromagnetic plate and is analogous to the tunneling anisotropic magnetoresistance, which originates from the spin-orbit interaction. This can be an important effect in magnetic sensor applications.

Ferroelectric and Magnetodielectric Properties of Cobalt-Doped Sr x Ba 1−x Nb 2 O 6 Ceramics

Abstract: Relaxor ferroelectrics Sr0.5Ba0.5Nb2O6 (SBN50) and Sr0.4Ba0.6Nb2O6 (SBN40), both pure and cobalt (Co) doped, have been synthesized and investigated to␣understand possible interaction between magnetic and electric order parameters. Synthesis was carried out via ceramic route. This paper reports the synthesis, crystal structure, dielectric properties, P–E hysteresis loops, M–H hysteresis loops, and magnetocapacitance (M c) of the Co-doped SBN compositions. All compositions were observed to exhibit useful values of M c, especially at frequencies less than 10 kHz.

Probing Spin Accumulation induced Magnetocapacitance in a Single Electron Transistor

Abstract: The interplay between spin and charge in solids is currently among the most discussed topics in condensed matter physics. Such interplay gives rise to magneto-electric coupling, which in the case of solids was named magneto-electric effect, as predicted by Curie on the basis of symmetry considerations. This effect enables the manipulation of magnetization using electrical field or, conversely, the manipulation of electrical polarization by magnetic field. The latter is known as the magnetocapacitance effect. Here, we show that non-equilibrium spin accumulation can induce tunnel magnetocapacitance through the formation of a tiny charge dipole. This dipole can effectively give rise to an additional serial capacitance, which represents an extra charging energy that the tunneling electrons would encounter. In the sequential tunneling regime, this extra energy can be understood as the energy required for a single spin to flip. A ferromagnetic single-electron-transistor with tunable magnetic configuration is utilized to demonstrate the proposed mechanism. It is found that the extra threshold energy is experienced only by electrons entering the islands, bringing about asymmetry in the measured Coulomb diamond. This asymmetry is an unambiguous evidence of spin accumulation induced tunnel magnetocapacitance, and the measured magnetocapacitance value is as high as 40%.