Y-type Structure Research Articles

A Y-Type Air-Cooled Battery Thermal Management System with a Short Airflow Path for Temperature Uniformity

A Y-type air-cooled structure has been proposed to improve the heat dissipation efficiency and temperature uniformity of battery thermal management systems (BTMSs) by reducing the flow path of air. By combining computational fluid dynamics (CFD) methods, the influence of the depths of the distribution and convergence plenums on the airflow velocity through battery cells was analyzed to improve heat dissipation efficiency. Adjusting the width of the first and ninth cooling channels can change the air velocity of these two channels, thereby improving the temperature uniformity of the BTMS. Further discussion was conducted regarding the influences of inlet and outlet depths. When the inlet width and outlet width were 20 mm, the maximum temperature and maximum temperature difference of the Y-type BTMS were 39.84 °C and 0.066 °C at a discharge rate of 2.5 °C, respectively; these temperatures were 1.537 °C (3.68%) and 0.059 °C (47.2%) lower than those of the T-type model. Meanwhile, the energy consumption of the sample also decreased by 13.1%. The results indicate that the heat dissipation performance of the proposed Y-type BTMS was improved, achieving excellent temperature uniformity, and the energy consumption was also reduced.

Optimizations of structure stiffnesses and sensitivities of Y-type six-axis force/torque sensor

PurposeThe six-axis force/torque sensor based on a Y-type structure has the advantages of simple structure, small space volume, low cost and wide application prospects. To meet the overall structural stiffness requirements and sensor performance requirements in robot engineering applications, this paper aims to propose a Y-type six-axis force/torque sensor.Design/methodology/approachThe performance indicators such as each component sensitivities and stiffnesses of the sensor were selected as optimization objectives. The multiobjective optimization equations were established. A multiple quadratic response surface in ANSYS Workbench was modeled by using the central composite design experimental method. The optimal manufacturing structural parameters were obtained by using multiobjective genetic algorithm.FindingsThe sensor was optimized and the simulation results show that the overload resistance of the sensor is 200%F.S., and the axial stiffness, radial stiffness, bending stiffness and torsional stiffness are 14.981 kN/mm, 16.855 kN/mm, 2.0939 kN m/rad and 6.4432 kN m/rad, respectively, which meet the design requirements, and the sensitivities of each component of the optimized sensor have been well increased to be 2.969, 2.762, 4.010, 2.762, 2.653 and 2.760 times as those of the sensor with initial structural parameters. The sensor prototype with optimized parameters was produced. According to the calibration experiment of the sensor, the maximum Class I and II errors and measurement uncertainty of each force/torque component of the sensor are 1.835%F.S., 1.018%F.S. and 1.606%F.S., respectively. All of them are below the required 2%F.S.Originality/valueHence, the conclusion can be drawn that the sensor has excellent comprehensive performance and meets the expected practical engineering requirements.

Complex magnetic interactions and critical behavior analysis in quaternary CoFeV0.8Mn0.2Si Heusler alloy

We investigate the magnetic behavior and critical exponents of quaternary CoFeV0.8Mn0.2Si Heusler alloy to understand the interactions across the Curie temperature (TC). The Rietveld refinement of the x-ray diffraction pattern with the space group F4¯3m confirms a single-phase cubic Y-type crystal structure. The magnetic susceptibility χ(T) data show a ferromagnetic nature with a second-order phase transition from paramagnetic to ferromagnetic at 446±1 K. The saturation magnetization at 5 K is found to be 2.2 μB/f.u., which is close to the Slater–Pauling rule and indicates its half-metallic nature. The values of asymptotic critical exponents (β, γ, and δ) and the TC are extracted through detailed analytical analysis including the modified Arrott plot, the Kouvel–Fisher (K–F) method, and the Widom scaling relation. Interestingly, the estimated values of β=0.369 and γ=1.445 closely approximate the theoretical values of the 3D Heisenberg model across the TC and validate the second-order thermodynamic phase transition. The obtained exponents lead to the collapse of renormalized isotherms, represented by the relationship between the magnetization (m) and the applied magnetic field (h), into two distinct branches above and below the TC, which validates the reliability of the analysis. Furthermore, these exponents suggest that the spin interaction follows a decay pattern of J(r)∼r−4.99, indicating a short-range magnetic ordering, akin to the itinerant-electron 3D Heisenberg model.

Ultra-high-performance graphene-based bulk materials strengthened by Y-type connection structure

The strategic design and assembly of bulk graphene materials represent a pivotal advancement for harnessing the inherent properties of graphene in practical applications. However, fabricating high-strength graphene-based bulk materials from graphene powders presents a significant challenge, primarily due to interlayer slippage between the graphene layers. Here, a unique Y-type connection structure was found in few-layer graphene synthesized by self-propagating high-temperature synthesis (SHS) and subsequently retained in graphene-based bulk materials prepared by spark plasma sintering (SPS) process. The Y-type connection structure and defect-induced linkages serve to cross-link the graphene-based bulk materials. Consequently, the bulk material exhibited an ultra-high compressive strength, reaching 2.14 GPa, supported by Molecular dynamics (MD) simulations which demonstrated that the Y-type connection structure increases the shear modulus and the load transfer rate. The Y-type connection structure plays a vital role in reinforcing the strength of graphene-based bulk materials, offering valuable insights for the microstructural design and property augmentation of other graphene-derived materials. Besides it’s ultra-high compressive strength, the graphene-based bulk material also performs a low thermal expansion coefficient (0.5 × 10−6 K−1), high electrical conductivity (1.47 × 105 S·m−1) and exceptional EMI shielding capability.

Substitution effects on Y-type hexaferrites’ magnetic characteristics

The effect is discussed of the partial replacement of the Me2+ in the Y-type hexaferrite crystal structure with non-magnetic (Mg2+) and magnetic (Ni2+) cations on the observed magnetic characteristics of Ba0.5Sr1.5Me2Fe12O22. Y-type hexaferrite powder material was prepared by citric acid sol-gel self-ignition and sintering at 1170 °C in air to reach Ba0.5Sr1.5MgxNiyFe12O22. To determine the magnetic phase transitions, the ZFC/FC magnetisation was followed in magnetic fields of 50 Oe and 100 Oe between 4.2 K and 300 K; this was complemented with hysteresis loops recorded at the end temperatures. The results show that combining the magnetic Ni2+ with the nonmagnetic Mg2+ in Ba0.5Sr1.5 Me2Fe12O22 can be effective in controlling the magnetic interactions to regulate the temperature of the magnetic transition from helical to ferrimagnetic arrangement above room temperature.

Bridging graphene sheets to ultra-high-performance graphene-based bulk materials via Si-C bonding and Y-type carbon structure

Graphene is the strongest material ever identified. However, the fabrication of graphene-based bulk materials from graphene powders presents a significant challenge. Here, a new strategy to fabricate high performance graphene based bulk materials by introducing silicon nanoparticle is proposed. Consequently, ultra-high compressive strength and high flexural strength are achieved, measuring as high as 1102 MPa and 455 MPa, respectively. The compressive strength at the microscale even reaches a remarkable 5.17 GPa. The superior strength of the bulk material is primarily attributed to the Y-type carbon structure and Si-C bonds. The Y-type carbon structures in graphene, produced by the self-propagating high-temperature synthesis (SHS) method, and the Si-C covalent bonds formed at the interface between graphene and SiC contribute to a tight linkage of graphene sheets, thereby preventing slippage of graphene sheets. In addition, the microstructure evolution process of Si-SHS-graphene bulk material is clarified. With the introduction of silicon nanoparticles, the oxidation resistance of graphene based bulk materials is substantially improved, the weight loss is around 6% after oxidized at 1000 °C. This study carries extensive implications for understanding the impact of Y-type carbon structures and the effect of Si-C bonds in graphene-based bulk materials.

An insight on the origin of half-metallicity of new equiatomic quaternary Heusler alloys PtRuTiZ (Z = Al/Si): GGA and GGA + U approaches

In this paper, we have presented a comparative investigation of a new equiatomic quaternary Heusler alloy PtRuTiZ (Z = Al and Si) under the GGA and GGA + U schemes and search for its possibility as a half-metallic material for spintronic devices. These alloys, which crystallize in a magnetic phase of LiMgPdSn (Y-type) structure with space group F-43 m, are thermodynamically and mechanically stable. The electronic properties predict these materials to be half metal under the GGA + U scheme considering the strong exchange splitting among the d – orbital of transition metals with a half-metallic gap of 0.07 eV and 0.1 eV for PtRuTiAl and PtRuTiSi, respectively signifying their prospect in power electronic applications. Here, PtRuTiSi is rigid and stiffer than PtRuTiAl and their magnetic properties also follow the Slater – Pauling rule of MT = ZT – 24 under the GGA + U scheme. The high range of pressure that PtRuTiSi (-1 GPa to 14 GPa) can retain its half-metallic behavior as compared to PtRuTiAl (-3 GPa to 4 GPa) may be linked to their bulk modulus.

Numerical Optimization of the Dendritic Arm of a Radial Gate Based on Stability and Light Weight

A new dendritic arm structure was proposed to achieve the stability and lightness of a large-scale radial gate arm. The arm structure was arranged in accordance with the current gate design specifications for steel. The optimization aims were to achieve the highest possible overall structural stability and the lowest possible weight. As the failure criterion for the entire structure, the simultaneous instability of the trunks and branches of the dendritic arm was considered. The constraints of strength, stiffness, and stability were identified, and an optimization model of a dendritic arm with two branches was established. A geometric and material nonlinear buckling analysis and optimization solution was implemented for the dendritic arm with a different radius, type, and unit rigidity ratios. Compared to a conventional radial gate structure with two arms, the Y-type dendritic arm structure was lighter and more stable. The optimal dendritic arm had the following parameter settings: the angle ratio between two branches and two arms was [1.92, 2.04], the unit rigidity ratio between the trunk and branch was [5.33, 6.02], the length ratio between the branch and trunk was [0.96, 1.09], the height ratio of the trunk and branch was 1.805, and the flange thickness ratio of the trunk and branch was 1.405. In this case, the overall buckling load ratio between the dendritic arm and two arms was [2.50, 4.34], and the material saving rate was [37, 53] (%). Within the aforementioned parameters, the Y-type dendritic arm performed better overall. Moreover, the radius of the radial gate had minimal influence on the shape and mechanical properties of the Y-type dendritic arm structure. This paper proposes a dendritic arm that can be utilized in most radial gate projects.

Half-metallic ferromagnetism in new quaternary Heusler alloys CoX’YP (X’ = Cr and Fe)

ABSTRACT In this study, we investigated the structural, electronic and magnetic properties of new quaternary Heusler alloys CoX'YP (X’ = Cr and Fe) using the accurate full-potential linearised augmented plane waves with local orbitals (FP-LAPW + lo) under the framework of the density functional theory (DFT) and the WIEN2k package. The generalised gradient approximation (GGA) is chosen to treat the exchange–correlation (XC) energy. The structural properties of the presented alloys are investigated in order to determine their structural parameters at equilibrium, such as: the lattice constant (a0 ), the bulk modulus (B0 ) and its first pressure derivative (B’). The structural stability of the CoCrYP and CoFeYP alloys is found in Y-type (I) structure, while their magnetic stability is reported in ferromagnetic phase. The electronic properties of the studied materials show the complete half-metallic character. The magnetic properties reveal that the total magnetic moment of the two alloys is found in integer value, obeying the Slater-Pauling rule. Furthermore, the calculated local magnetic moments of Co and X’ atoms are found with opposite signs, confirming the ferrimagnetic coupling within these compounds. According to the electronic and magnetic results found in this approach, we conclude that the compounds CoCrYP and CoFeYP are full half-metallic ferromagnetic materials.

Three-Way DNA Junction as an End Label for DNA in Atomic Force Microscopy Studies.

Atomic Force Microscopy (AFM) is widely used for topographic imaging of DNA and protein-DNA complexes in ambient conditions with nanometer resolution. In AFM studies of protein-DNA complexes, identifying the protein’s location on the DNA substrate is one of the major goals. Such studies require distinguishing between the DNA ends, which can be accomplished by end-specific labeling of the DNA substrate. We selected as labels three-way DNA junctions (3WJ) assembled from synthetic DNA oligonucleotides with two arms of 39–40 bp each. The third arm has a three-nucleotide overhang, GCT, which is paired with the sticky end of the DNA substrate generated by the SapI enzyme. Ligation of the 3WJ results in the formation of a Y-type structure at the end of the linear DNA mole cule, which is routinely identified in the AFM images. The yield of labeling is 69%. The relative orientation of arms in the Y-end varies, such dynamics were directly visualized with time-lapse AFM studies using high-speed AFM (HS-AFM). This labeling approach was applied to the characterization of the nucleosome arrays assembled on different DNA templates. HS-AFM experiments revealed a high dynamic of nucleosomes resulting in a spontaneous unraveling followed by disassembly of nucleosomes.

Magnetic properties and possible martensitic transformation in equiatomic quaternary Heusler alloy CoMnNiSn

Equiatomic quaternary Heusler alloy CoMnNiSn has been synthesized in both bulk and ribbon form to explain the contradictions in the magnetic properties and possible martensitic transformation between different literature. The structure, magnetic properties and electronic structure of CoMnNiSn were investigated both theoretically and experimentally. A cubic Heusler phase can be identified in the XRD patterns. A small amount of secondary phase is observed in bulk CoMnNiSn while it is eliminated in the melt-spun ribbons. The saturation magnetization Ms at 5 K of bulk and ribbon CoMnNiSn are 4.85 μB/f.u. and 4.76 μB/f.u., respectively. This and also the calculation results suggest that ferromagnetic ground state has been established in CoMnNiSn samples. There is no trace of martensitic transformation in CoMnNiSn bulk and ribbon samples. The L21B atomic disorder can be responsible for this, which comes from the random occupation of Co/Ni at A, C sites in the cubic lattice of CoMnNiSn and has a higher stability comparing with the ordered Y-type structure. This suppression effect is further explained by the weakening of the Jahn-Teller effect in the austenite DOS of L21B type CoMnNiSn. All this calls for more attention to the effects of atomic disorder in the design of magnetic shape memory alloys in equiatomic quaternary Heusler alloys.

Synthesis and Characterization of Praseodymium substituted Y-type hexaferrites

Y-type Hexagonal ferrites have acquired much more attention due to their multiferroic qualities. The Standard formula for Y-type Hexagonal ferrites is given as (A2Me2Fe12O22) where A= Sr2+, Ba2+, Pb2+, La2+ and Me = Bivalent metal In Y-type hexagonal structure, two tetrahedral sites and four octahedral sites are inhabited with small cations. Multiferroic properties of Y-type hexaferrites can be affected by different factors such as synthesis methods, amount of substitution, sintering temperature and chemical composition. For the present study Praseodymium substituted strontium-based Y-type hexaferrites with chemical composition Sr2Ni2-xPrxFe12O22(where x=0.0 and 0.1) has been synthesized using sol-gel method and characterized byX-ray diffraction, Fourier Transform Infrared Spectroscopy and Impedance Analyzer. The structural analysis through XRD and FTIR verified the phase formation of Y-type ferrites having hexagonal structure. The XRD data reveals the increase in the volume, and decrease in particle size with praseodymium substitution. In FTIR, resulting peaks observed in two samples lie between 400-600 cm-1 which indicates the vibrational stretching in Fe-O bond.

Novel half-metallicity in Y-type equiatomic quaternary Heusler alloys XFeCrAl (X = Rh, Pd, and Pt)

In the present study, we performed theoretical investigations to understand the origin of the half-metallic properties of new types of equiatomic quaternary Heusler compounds XFeCrAl (X = Rh, Pd, and Pt) and their possible applications in spintronics. These compounds crystallize in the Y-type structure with the F-43m space group, where the constitutive atoms are located in their non-equivalent positions in Type-I. Furthermore, we verified the thermodynamic, chemical, mechanical, and dynamical stabilities of these alloys. The results showed that they are stable in the magnetic phase where the optimized lattice constants are X-dependent. Among the three sample alloys, PdFeCrAl was shown to be the hardest with a brittle nature, whereas the others were found to be ductile. Analyses of the energy bands and magnetic profiles indicated the 100% spin-polarized, half-metallic, ferromagnetic natures of PdFeCrAl and PtFeCrAl, with EHM values of 0.09 eV and 0.03 eV, respectively, whereas RhFeCrAl is a nearly half-metallic ferrimagnet with 91% spin-polarization and it tends to act as a half-metal under the effect of uniform pressure. Their half-metallic nature can be expected because of the wide range of uniform strain due to their high bulk moduli. Thus, they have novel characteristics with lattice constants in the ranges of 5.55–5.64 Å, 5.53–6.04 Å, and 5.55–5.99 Å for RhFeCrAl, PdFeCrAl, and PtFeCrAl, respectively. The total magnetic moments of 1.98 μB, 2.99 μB, and 3.0 μB per formula unit obtained for RhFeCrAl, PdFeCrAl, and PtFeCrAl follow the Slater–Pauling rule. The highest Curie temperature (1113 K) obtained for PtFeCrAl demonstrates its feasible applications in spintronics with a high temperature limit.

Y-type DNA structure stabilized p-type CuS quantum dots to quench photocurrent of ternary heterostructure for sensitive photoelectrochemical detection of miRNA

Herein, a p-n quenching photoelectrochemical (PEC) biosensor is constructed for the ultrasensitive detection of miRNA-21 which the SnO2/CdCO3/CdS ternary composite nanomaterial is used as a signal indicator and the Y-type DNA structure stabilized p-type CuS quantum dot (QD) is employed as a signal quencher. Constructing the cascade energy level structure by using three photosensitive materials, in which stannic oxide (SnO2) is used as the photoactive material and cadmium sulfide (CdS) and cadmium carbonate (CdCO3) are served as the sensitizers. The prepared SnO2/CdCO3/CdS cascade co-sensitization structure with significantly improved photocurrent signal can inhibit the recombination of photogenerated electrons and holes, thereby dramatically enhancing the initial photocurrent response. Amounts of single strands DNA (assistant DNA) are output via the exponential strand displacement amplification (E-SDA) when miRNA-21 is present. The output assistant DNA can stabilize the CuS QD by forming stable Y-type DNA nanostructure on the surface of SnO2/CdCO3/CdS modified electrode. Therefore, the PEC signal of SnO2/CdCO3/CdS ternary composite nanomaterial is greatly quenched, because of the competitive consumption of exciting light energy and electron donors, as well as the steric effect of Y-type DNA structure. The linear range of the biosensor is from 10 fM to 1 μM with the detection limit down to 3.25 fM.

Magnetic and electrical properties of Ba2Co2Fe12O22/PANI composites prepared by insitu polymerization

Y-type hexaferrite with nominal composition Ba2Co2Fe12O22 was synthesized by sol-gel method. The synthesized hexaferrite filler was mixed in 5 wt%, 15 wt% and 25 wt% respectively with Polyaniline (PANI) by insitu polymerization method to get hexaferrite-PANI composites. The synthesized samples were characterized by DC resistivity, XRD, VSM and dielectric measurements. The X-ray diffraction of polyaniline exhibit amorphous nature, whereas Ba2Co2Fe12O22exhibit single phase Y-type structure. Room temperature resistivity of the composites increased with increasing hexaferrite filler from 2.29 × 101 to 2.59 × 104 Ω-cm. Dielectric constant and complex dielectric constant measured in the frequency range of 1 Hz to 1 MHz. Both the real and imaginary parts of dielectric constant decreased with the increase of hexaferrite contents. AC conductivity was decreased with increasing Co2Y hexaferrite contents in PANI matrix and increased with increasing frequency following Maxwell-Wagner model. The saturation magnetization was observed to increase significantly with increasing hexaferrite filler, as it depends on volume fraction of magnetic particles and demagnetizing field produced by non-magnetic particles. Coercivity on average decreased with increasing hexaferrite filler which was due to the decrease in the inter particle distance and hence magneto static interactions enhanced amongst the particles. These composite materials are considered useful for applications of these materials in EMI shielding in low frequency range with added advantage of flexibility.

Half-metallic ferromagnetism and Ru-induced localization in quaternary Heusler alloy CoRuMnSi

We report a combined theoretical and experimental investigation of half-metallic ferromagnetism in equiatomic quaternary Heusler alloy CoRuMnSi. Room temperature XRD analysis reveals that the alloy crystallizes in L21 disordered structure instead of pristine Y-type structure due to 50% swap disorder between the tetrahedral sites, i.e., Co and Ru atoms. Magnetization measurements reveal a net magnetization of nearly 4 μB with Curie temperature, TC of ∼780 K. Resistivity measurement reveals the presence of localization effect below 35 K while above 100 K, a linear dependence is observed. The majority spin band near the Fermi level clearly indicates the overlap of flat eg bands with sharply varying conduction bands that are responsible for the localization. In-depth analysis of the projected atomic d-orbital character of band structure reveals unusual bonding, giving rise to the flat eg bands purely arising out of Ru ions. Co-Ru swap disorder calculations indicate the robustness of half-metallic nature, even when the structure changes from Y-type to L21-type, with no major change in the net magnetization of the system. Thus, high TC, robust stability, and half-metallic nature make this alloy a promising candidate for further exploration from the point of view of applied spintronics.

Simultaneous measurement of SO2 and NO2 concentration using an optical fiber-based LP-DOAS system

SO2 and NO2 are the most important pollution in atmosphere. An optimized long path (LP) differential optical absorption spectroscopy (DOAS) system of high light intensity at an ultraviolet (UV) wavelength is proposed and used to measure the concentration of SO2 and NO2 simultaneously. In contrast to the traditional DOAS, the system adopted a Y-type optical fiber structure instead of a combination of mirrors in the telescope. The UV light intensity test shows that the light intensity of UV can arrive to above 80% of the max measuring range when the light path reaches 135 m, and the integral time of the spectrograph is only 15 ms. The system is proved to be efficacious through laboratory calibration. The maximum error of SO2 calibration is 4.19%, and is 5.22% for NO2. The error of the SO2 and NO2 mixture calibration is within 10%. Field measurement is implemented in a wastewater treatment plant in winter. The measurement light path is 738 m. The concentration of SO2 varies from 6 μg/m3 (2.26 ppb) to 20 μg/m3 (7.52 ppb), and the concentration of NO2 varies from 100 μg/m3 (53.2 ppb) to 200 μg/m3 (106.4 ppb) approximately. The results are in accordance with the data from a monitoring station nearby in magnitude order and variation tendency mostly.

Molecular dynamics simulation of Y-type nanomotors with different angles in aqueous solution

Nanomotors are of great importance when studying nanoelectromechanical systems that contain carbon nanotube (CNT) based nanomotors for controlled motion in water using a rotating electric field. In this paper, Y-type nanomotor structures based on CNTs immersed in an aqueous solution are designed, and systems with different Y-type structure angles are simulated using molecular dynamics. The simulation results suggest that when the rotating electric field speed is appropriate, changing the Y-type structure angle can adjust the hysteresis (forward and backward motion) of nanomotor rotors during rotation. Precise control over the rotation angle of the nanomotor rotor improves its working efficiency. The enclosed simulation results are an important reference when designing nanoscale propellers and complex structured nanogear systems in aqueous solutions.

Ordering induced transformation from high-entropy to Heusler CrVTiAl alloy

The equimolar quaternary CrVTiAl is not only a potential spin filter, but also a light-weight high entropy alloy. The excellent performance strongly depends on the order degree. We use the ab initio calculation to investigate the structural, magnetic, elastic properties of CrVTiAl as a function of the order degree describing phase from full disorder A2 to DO3, B2, and L21 to full order Y-type (LiMgPdSn-type) structure. The Cr-Al bonding plays a key role in the local magnetic moments, further induces the increasing lattice parameter and decreasing elastic constants. Furthermore, the effect of preferred sites on mechanical properties is discussed.

Study of the Structural and Magnetic Properties of Co-Substituted Ba2Mg2Fe12O22 Hexaferrites Synthesized by Sonochemical Co-Precipitation

Ba2Mg0.4Co1.6Fe12O22 was prepared in powder form by sonochemical co-precipitation and examined by X-ray diffraction, Mössbauer spectroscopy and magnetization measurements. Careful XRD data analyses revealed the Y-type hexaferrite structure as an almost pure phase with a very small amount of CoFe2O4 as an impurity phase (about 1.4%). No substantial changes were observed in the unit cell parameters of Ba2Mg0.4Co1.6Fe12O22 in comparison with the unsubstituted compound. The Mössbauer parameters for Ba2Mg0.4Co1.6Fe12O22 were close to those previously found (within the limits of uncertainty) for undoped Ba2Mg2Fe12O22. Isomer shifts (0.27–0.38 mm/s) typical for high-spin Fe3+ in various environments were evaluated and no ferrous Fe2+ form was observed. However, despite the indicated lack of changes in the iron oxidation state, the cationic substitution resulted in a significant increase in the magnetization and in a modification of the thermomagnetic curves. The magnetization values at 50 kOe were 34.5 emu/g at 4.2 K and 30.5 emu/g at 300 K. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves were measured in magnetic fields of 50 Oe, 100 Oe, 500 Oe and 1000 Oe, and revealed the presence of two magnetic phase transitions. Both transitions are shifted to higher temperatures compared to the undoped compound, while the ferrimagnetic arrangement at room temperature is transformed to a helical spin order at about 195 K, which is considered to be a prerequisite for the material to exhibit multiferroic properties.