Showing papers on "Transition temperature published in 2007"
TL;DR: The ability to rapidly process polymers with inaccessible order-disorder transition temperatures suggests zone annealing as a route toward more robust nanomanufacturing methods based on block copolymer self-assembly.
Abstract: We report measurements of rapid ordering and preferential alignment in block copolymer films zone annealed below the order-disorder transition temperature. The orientational correlation lengths measured after approximately 5 h above the glass-transition temperature ( approximately 2 microm) were an order of magnitude greater than that obtained under equivalent static annealing. The ability to rapidly process polymers with inaccessible order-disorder transition temperatures suggests zone annealing as a route toward more robust nanomanufacturing methods based on block copolymer self-assembly.
205 citations
TL;DR: The most stable vapor-deposited IMC glasses had thermodynamic stabilities equivalent to ordinary glasses aged at 295 K for 7 months, and are attributed to enhanced surface mobility at substrate temperatures near 0.6Tg.
Abstract: Physical vapor deposition of indomethacin (IMC) was used to prepare glasses with unusual thermodynamic and kinetic stability. By varying the substrate temperature during the deposition from 190 K to the glass transition temperature (Tg=315 K), it was determined that depositions near 0.85Tg (265 K) resulted in the most stable IMC glasses regardless of substrate. Differential scanning calorimetry of samples deposited at 265 K indicated that the enthalpy was 8 J/g less than the ordinary glass prepared by cooling the liquid, corresponding to a 20 K reduction in the fictive temperature. Deposition at 265 K also resulted in the greatest kinetic stability, as indicated by the highest onset temperature. The most stable vapor-deposited IMC glasses had thermodynamic stabilities equivalent to ordinary glasses aged at 295 K for 7 months. We attribute the creation of stable IMC glasses via vapor deposition to enhanced surface mobility. At substrate temperatures near 0.6Tg, this mobility is diminished or absent, resulting in low stability, vapor-deposited glasses.
170 citations
TL;DR: In this paper, a simple model based on Landau theory is developed as a guide for the straightforward production of samples with ferroelectric properties designed for particular applications, and the polarization of PbTiO3/SrTiO 3 superlattices is experimentally tuned from 0-60 mu C/cm(-2) and the transition temperature from room temperature to 1000 K while maintaining a perfect crystal structure and low leakage currents.
Abstract: The polarization of PbTiO3/SrTiO3 superlattices is experimentally tuned from 0-60 mu C/cm(-2) and the transition temperature from room temperature to 1000 K while maintaining a perfect crystal structure and low leakage currents (see figure). A simple model based on Landau theory is developed as a guide for the straightforward production of samples with ferroelectric properties designed for particular applications.
164 citations
TL;DR: In this article, the magnetodielectric properties of well-ordered epitaxial La2CoMnO6 films were investigated under applied magnetic fields up to 50kOe.
Abstract: We report on the magnetodielectric properties of well-ordered epitaxial La2CoMnO6 films. The temperature dependence of the dielectric constant is measured in the 10–105Hz frequency range under applied magnetic fields up to 50kOe. As temperature is lowered, the dielectric constant decreases in the ferromagnetic regime and approaches a plateau below 100K. A significant enhancement in the dielectric constant under applied magnetic field is observed only in the ferromagnetic phase regime culminating around the transition temperature, while it is absent in the paramagnetic phase regime. Using Arrott plots, we also demonstrate that these films exhibit a second-order phase transition at their Curie temperature. The observed magnetodielectric characteristics of the films are interpreted using the phenomenological theory.
163 citations
TL;DR: In this article, the authors investigated the strain-rate dependence of the brittle-to-ductile transition (BDT) temperature in pre-cracked tungsten single-crystals and polycrystals.
Abstract: We have investigated the strain-rate dependence of the brittle-to-ductile transition (BDT) temperature in pre-cracked tungsten single-crystals and polycrystals. There is an unambiguous Arrhenius relationship over four decades of strain rate, giving an activation energy for the process controlling the BDT of 1.05 eV. This is equal to the activation energy for double-kink formation on screw dislocations, suggesting that their motion controls the brittle–ductile transition.
161 citations
TL;DR: The spatial charge arrangement of a typical quasi-two-dimensional organic conductor α-(BEDT-TTF) 2 I 3 is revealed by single crystal structure analysis using synchrotron radiation.
Abstract: The spatial charge arrangement of a typical quasi-two-dimensional organic conductor α-(BEDT-TTF) 2 I 3 is revealed by single crystal structure analysis using synchrotron radiation. The results show that the horizontal-stripe-type structure, which was suggested by the mean field theory, is established. We also find the charge disproportionation above the metal–insulator transition temperature and a significant change in the transfer integrals caused by the phase transition. Our result elucidates the insulating phase of this material as the 2 k F charge density localization.
150 citations
TL;DR: In this article, the Fe-Al phase diagram has been experimentally re-investigated by differential thermal analysis on 64 alloys with different compositions in the concentration range between 0 and 74 at% Al.
Abstract: The Fe – Al phase diagram has been experimentally re-investigated by differential thermal analysis on 64 alloys with different compositions in the concentration range between 0 and 74 at.% Al. For the melting temperatures, the existence of a shallow maximum at low Al-contents is proven experimentally for the first time. In the solid state, critical temperatures and invariant reactions as well as the order/disorder and ferro-/paramagnetic transitions occurring in the Fe-rich part of the binary system are studied in detail. For the most part, the present data confirm recent assessments of the Fe – Al phase diagram. Small corrections are suggested for some of the critical temperatures. Several effects related to the re-arrangement and annealing out of defects in the B2-ordered FeAl phase are also described. No effect which could be related to the K state has been found. Instead an effect was observed in the same temperature range but for a much wider range of compositions, which is probably due to t...
138 citations
TL;DR: The spatial charge arrangement of a typical quasi-two-dimensional organic conductor alpha-(BEDT-TTF)2I3 is revealed by single crystal structure analysis using synchrotron radiation as mentioned in this paper.
Abstract: The spatial charge arrangement of a typical quasi-two-dimensional organic conductor alpha-(BEDT-TTF)2I3 is revealed by single crystal structure analysis using synchrotron radiation. The results show that the horizontal stripe type structure, which was suggested by mean field theory, is established. We also find the charge disproportion above the metal-insulator transition temperature and a significant change in transfer integrals caused by the phase transition. Our result elucidates the insulating phase of this material as a 2k_F charge density localization.
135 citations
TL;DR: In this article, the lattice and electronic and magnetic transport properties of the antiperovskite structure of Mn3Zn1−xGexN compounds were investigated, and it was shown that the partial substitution of Ge for Zn induces a lattice contraction near the magnetic transition temperature.
Abstract: The lattice and electronic and magnetic transport properties of the antiperovskite structure Mn3Zn1−xGexN compounds were investigated. For Mn3ZnN, there is a magnetic transition from antiferromagnetic to paramagnetic near 185K. Correspondingly, the resistivity shows an abrupt drop, but any sudden change of lattice parameters is not found. However, it is interesting that the partial substitution of Ge for Zn induces a lattice contraction near the magnetic transition temperature, where a drop of the resistivity remain, and the transition temperature point increases and the temperature range is broadened with increasing doped Ge contents. The thermodynamics properties were also investigated.
128 citations
TL;DR: In this article, active white powdery tungstic acid (WPTA) was used as a substitutional dopant for reducing the phase transition temperature of vanadium dioxide nanopowders.
Abstract: Tungsten-doped vanadium dioxide (VO2) nanopowders were synthesized by thermolysis of (NH4)5[(VO)6(CO3)4(OH)9]·10H2O at low temperature with, to the best of our knowledge, active white powdery tungstic acid (WPTA) used as a substitutional dopant for the first time. The change in electrical resistance due to the semiconductor−metal transition was measured from −5 to 150 °C by the four-probe method. Differential scanning calorimetry and the resistance−temperature curve of the nanopowders indicated that the phase transition temperature of VO2 powders was 67.15 °C, but for W-doped VO2, the temperature was reduced to 26.46 °C. The results indicated that WPTA was found to be exceptionally effective as a dopant for reducing the transition temperature.
120 citations
TL;DR: The experiments suggest that the shoulder transition and major transition arise from the defibrillation and denaturation of collagen, respectively.
Abstract: The denaturation of collagen solution in acetic acid has been investigated by using ultra-sensitive differential scanning calorimetry (US-DSC), circular dichroism (CD), and laser light scattering (LLS). US-DSC measurements reveal that the collagen exhibits a bimodal transition, i.e., there exists a shoulder transition before the major transition. Such a shoulder transition can recover from a cooling when the collagen is heated to a temperature below 35 degrees C. However, when the heating temperature is above 37 degrees C, both the shoulder and major transitions are irreversible. CD measurements demonstrate the content of triple helix slowly decreases with temperature at a temperature below 35 degrees C, but it drastically decreases at a higher temperature. Our experiments suggest that the shoulder transition and major transition arise from the defibrillation and denaturation of collagen, respectively. LLS measurements show the average hydrodynamic radius R(h), radius of gyration R(g)of the collagen gradually decrease before a sharp decrease at a higher temperature. Meanwhile, the ratio R(g)/R(h) gradually increases at a temperature below approximately 34 degrees C and drastically increases in the range 34-40 degrees C, further indicating the defibrillation of collagen before the denaturation.
TL;DR: In this paper, the authors report magnetization and differential thermal analysis measurements as a function of pressure accross the martensitic transition in magnetically superelastic Ni-Mn-In alloys.
Abstract: We report magnetization and differential thermal analysis measurements as a function of pressure accross the martensitic transition in magnetically superelastic Ni-Mn-In alloys. It is found that the properties of the martensitic transformation are significantly affected by the application of pressure. All transition temperatures shift to higher values with increasing pressure. The largest rate of temperature shift with pressure has been found for Ni$_{50}$Mn$_{34}$In$_{16}$ as a consequence of its small entropy change at the transition. Such a strong pressure dependence of the transition temperature opens up the possibility of inducing the martensitic transition by applying relatively low hydrostatic pressures.
TL;DR: In this paper, the effect of magnetic field on a nonstoichiometric Heusler alloy Ni50Mn35In15 that undergoes a martensitic as well as a magnetic transition near room temperature was studied.
Abstract: We have studied the effect of magnetic field on a nonstoichiometric Heusler alloy Ni50Mn35In15 that undergoes a martensitic as well as a magnetic transition near room temperature. Temperature dependent magnetization measurements demonstrate the influence of magnetic field on the structural phase transition temperature. From the study of magnetization as a function of applied field, we show the occurrence of inverse-magnetocaloric effect associated with this magneto-structural transition. The magnetic entropy change attains a value as high as 25J∕kgK (at 5T field) at room temperature as the alloy transforms from the austenitic to martensitic phase with a concomitant magnetic ordering.
TL;DR: In this article, the ferroelectric phase transition behavior in BaTiO3 was investigated for various annealing times, temperatures, and Ba/Ti ratios by means of a differential scanning calorimeter.
Abstract: The ferroelectric phase transition behavior in BaTiO3 was investigated for various annealing times, temperatures, and Ba/Ti ratios by means of a differential scanning calorimeter. Coupling these observations with powder X-ray diffraction and transmission electron microscopy allowed new insights into the barium oxide (BaO)–titanium dioxide (TiO2) phase diagram. The transition temperature was varied systematically with the Ba/Ti ratio at annealing temperatures from 1200° to 1400°C in air. The transition temperature decreased with increasing concentrations of BaO and TiO2 partial Schottky defects, and showed a discontinuous change at the phase boundaries. Beyond the solubility region, two peritectoid reactions were confirmed and revised; first around 1150°C for Ba1.054Ti0.946O2.946→Ba2TiO4+BaTiO3 and second 1250°C for BaTi2O5→Ba6Ti17O40+BaTiO3, respectively. All other regimes of the BaO–TiO2 were found to be consistent with the reported diagrams in the literature.
TL;DR: In this paper, the effect of magnetic field on a non-stoichiometric Heusler alloy Ni$50$Mn$_{35}$In$15}$ that undergoes a martensitic as well as a magnetic transition near room temperature was studied.
Abstract: We have studied the effect of magnetic field on a non-stoichiometric Heusler alloy Ni$_{50}$Mn$_{35}$In$_{15}$ that undergoes a martensitic as well as a magnetic transition near room temperature. Temperature dependent magnetization measurements demonstrate the influence of magnetic field on the structural phase transition temperature. From the study of magnetization as a function of applied field, we show the occurrence of inverse-magnetocaloric effect associated with this magneto-structural transition. The magnetic entropy change attains a value as high as 25 J/kg-K (at 5 T field) at room temperature as the alloy transforms from the austenitic to martensitic phase with a concomitant magnetic ordering.
TL;DR: In this article, the metal-insulator transition in VO2 thin films synthesized by means of rf sputtering from a VO2 target is compared with conventional reactive sputtering.
Abstract: The study of metal-insulator transition (MIT) in VO2 thin films synthesized by means of rf sputtering from a VO2 target is presented. A comparison with conventional reactive sputtering from a V target is also given. Detailed x-ray diffraction analysis, electrical resistance switching, and infrared optical reflectance measurements confirm that our sputtering technique yields high-quality VO2 films. We discuss in depth how synthesis conditions affect MIT parameters derived from temperature dependence of electrical resistance. Sharp MIT is observed in films sputtered on technologically important Si substrates. The choice of Si (or sapphire) substrates results in the transition temperature above (below) the values obtained for single VO2 crystals. The MIT becomes narrower and stronger in thinner films. This is consistent with the assumption that the increased width of the MIT in thin films with respect to single crystals is the result of averaging of the transition parameters over a distribution of crystallit...
TL;DR: The glass transition temperature measured by DMTA from the change in slope in storage modulus was 55°C, which was 10.5°C lower than the value measured by tan δ peak.
TL;DR: In this paper, the effect of oxygen stoichiometry on the transition metal ordering and electrochemical activity of LiMn 2− x Ni x O 4 solid solutions was investigated by means of infrared spectroscopy, thermogravimetric analysis and galvanostatic measurements.
TL;DR: In this article, a photoemission study on reactively sputtered W-doped VO2 films by high-resolution photoelectron spectroscopy was carried out and it was shown that increase in tungsten content in the film results in decreased transition temperature and smeared metal-semiconductor transition.
TL;DR: In this article, the structural stability and superconducting properties of ultrathin lead-bismuth alloys can be tuned by adding extra electrons via bismuth alloying.
Abstract: Quantum confinement of itinerant electrons in atomically smooth ultrathin lead films produces strong oscillations in the thickness-dependent film energy. By adding extra electrons via bismuth alloying, we showed that both the structural stability and the superconducting properties of such films can be tuned. The phase boundary (upper critical field) between the superconducting vortex state and the normal state indicates an anomalous suppression of superconducting order just below the critical temperature, Tc. This suppression varies systematically with the film thickness and the bismuth content and can be parametrized in terms of a characteristic temperature, Tc* (less than Tc), that is inversely proportional to the scattering mean free path. The results indicate that the isotropic nature of the superconductive pairing in bulk lead-bismuth alloys is altered in the quantum regime.
TL;DR: In this article, the authors examined the relative humidity (RH) affects the transition path and the transition temperatures of NH 4 NO 3 using in-situ microscopic Fourier Transform InfraRed spectroscopy.
Abstract: Solid ammonium nitrate (NH 4 NO 3 ) exists in five stable polymorphic forms (designated as phases I, II, III, IV, and V) below its melting point at around 170°C. Phase IV is stable in a temperature range of −17°C ∼ 32°C and is the only phase that has been considered by the atmospheric research community until recently. In this study, we examine the IV ↔ III phase transition of NH 4 NO 3 and how relative humidity (RH) affects the transition path and the transition temperatures using in-situ microscopic Fourier Transform InfraRed spectroscopy. Two kinds of NH 4 NO 3 samples, powder produced from grinding commercially produced chemicals and single particles obtained by efflorescence of droplets on PTFE filters, were studied. The powder samples exhibit the IV↔III phase transition and the transition temperature depends on the RH while the single particle samples exhibit only the IV↔II transition at about 52°C (forward) and 48°C (reverse), bypassing phase III, with transition temperatures independent of the RH....
TL;DR: In this paper, the authors used the 246 Landau potential with saturation terms to describe the elastic anomalies associated with octahedral tilting transitions in perovskites that are associated with the M and R points of the Brillouin zone.
Abstract: Landau theory has been used to develop expressions for the elastic anomalies that accompany octahedral tilting transitions in perovskites that are associated with the M and R points of the Brillouin zone. The master equation is a 246 Landau potential with saturation terms that provides phenomenological descriptions of transition sequences from a parent cubic structure through tetragonal or rhombohedral intermediates to orthorhombic or monoclinic product structures. Data from the literature have been used to determine values for all the coefficients required to generate a quantitative description of the Pm 3 m ↔ I 4/ mcm transition in SrTiO 3 , which is taken as a model system. Solutions to the Landau expansion have been adapted to include the general influence of hydrostatic pressure and non-hydrostatic stress on transition temperature and the evolution of the order parameter. Critical examination of elastic constant data from the literature reveals inconsistencies between the results of measurements on tetragonal samples using ultrasonic rather than Brillouin scattering methods. An internally consistent data set has, nevertheless, been assembled. Good qualitative agreement was obtained between the general pattern of calculated and observed variations of all the single crystal elastic constants, and semi-quantitative agreement was obtained for C 11 , C 33 , C 12 , and C 13 . Some inconsistencies remain in relation to the temperature dependence of the square of the soft mode frequencies in the tetragonal phase, which follow the square of the order parameter rather than its inverse susceptibility, but the 246 potential seems to provide a good description of the structural evolution of SrTiO 3 over a wide temperature interval up to the cubic-tetragonal transition point.
TL;DR: In this paper, the magnetocaloric effect has been studied on polycrystalline Ho5Pd2 compound, which undergoes magnetic field-induced first order metamagnetic transition from antiferromagnetic to ferromagnetic state below antiferrous transition temperature.
Abstract: The study of magnetocaloric effect has been performed on polycrystalline Ho5Pd2 compound, which undergoes magnetic field-induced first order metamagnetic transition from antiferromagnetic to ferromagnetic state below antiferromagnetic transition temperature. A large magnetic entropy change associated with the field-induced metamagnetic transition has been observed over a wide temperature range. The evaluated value of relative cooling power is 6.32J∕cm3 for a magnetic field change of 5T, which is even larger than that for reported best known magnetic refrigerant materials irrespective of the temperature range.
TL;DR: In this paper, the ferroelectric phase transition behavior in equilibrated nonstoichiometric BaTiO3 powder samples was characterized by a differential scanning calorimeter.
Abstract: The ferroelectric phase transition behavior in equilibrated nonstoichiometric BaTiO3 powder samples was characterized by a differential scanning calorimeter. The transition temperature (TC) and enthalpy of transition (ΔHTC) between the paraelectric and ferroelectric phases were varied systematically with defect concentrations through the Ba∕Ti ratio, temperature, and oxygen partial pressure [p(O2)]. It was observed that the different defects such as titanium, barium, and oxygen vacancies all contribute to the changes of TC and ΔHTC. The TC decreased with increasing concentration of TiO2 partial Schottky defects and BaO partial Schottky defects. The annealing temperature increased the TC due to a complex mechanism with the increase of full Schottky defect reactions. In terms of p(O2), TC is constant in the ionic compensation region, and increases with the nonstoichiometry in the electronically compensated p(O2) region.
TL;DR: Ba(Zr x Ti 1− x )O 3 ceramics with x ǫ = 0.10, 0.15 and 0.18 were prepared via solid state reaction as mentioned in this paper.
Abstract: Ba(Zr x Ti 1− x )O 3 ceramics with x = 0.10, 0.15 and 0.18 were prepared via solid state reaction. For the composition x = 0.10, ceramics with various grain sizes in the range 0.75–3.20 μm were obtained by sintering at various temperatures 1350–1500 °C. High permittivity (above 14,000 at the transition temperature) and losses smaller than 7% for temperatures below 120 °C, together with a shift of the Curie temperature towards lower values with increasing x , are characteristic to these ceramics. A ferroelectric-relaxor crossover takes place when x increases, with intermediate character for all the compositions. For the composition x = 0.10, the relaxor state is favoured by reducing the grain size.
TL;DR: Li2BiV5O15 was prepared by a mixed-oxide method, relatively at low temperature (i.e., 550°C). Room temperature XRD pattern confirms the formation of the compound with an orthorhombic crystal system as mentioned in this paper.
Abstract: The polycrystalline sample of Li2BiV5O15 was prepared by a mixed-oxide method, relatively at low temperature (i.e., 550 °C). Room temperature XRD pattern confirms the formation of the compound with an orthorhombic crystal system. Studies of dielectric properties show that the compound exhibits an anomaly at 416 °C (usually called transition temperature) at 50 and 100 kHz, with diffuse-type phase transition. The electrical parameters of the material were studied using complex impedance spectroscopy in a wide temperature (30–500 °C) and frequency (102–106 Hz) range. The compound exhibits non-Debye of relaxation process. The activation energy of the material was found to be ∼1.08 eV in the high temperature region.
TL;DR: In this article, it was shown that it is possible to induce room temperature ferromagnetism, exhibiting high transition temperature, in tin oxide thin films by introducing manganese in a SnO2 lattice.
Abstract: It has been possible to induce room temperature ferromagnetism, exhibiting high transition temperature, in tin oxide thin films by introducing manganese in a SnO2 lattice. The observed temperature dependence of the magnetization predicts a Curie temperature exceeding 550 K. A maximum saturation magnetic moment of 0.18±0.04 μB per Mn ion has been estimated for spray pyrolized Sn1−xMnxO2−δ thin films, with x=0.10. For Mn concentration (x) higher than 0.10, the films show linear behavior. The magnetization-versus-field studies indicate that the origin of ferromagnetism lies neither in ferromagnetic metal clusters nor in the presence of metastable phases. The structure factor calculations reveal that Mn has been incorporated in the SnO2 lattice. Also, the electron transport investigation indicates that there is a change of Mn occupancy from substitutional to interstitial sites of the SnO2 lattice when the Mn concentration exceeds 7.5 at. %. These films do not exhibit anomalous Hall effects at room temperature...
TL;DR: It is demonstrated that lithium is a superconductor at ambient pressure with a transition temperature of 0.4 mK, which would clearly lead to mutual competition between these two ordering phenomena under suitably prepared conditions.
Abstract: Elements in the alkali metal series are regarded as unlikely superconductors because of their monovalent character. A superconducting transition temperature as high as 20 K, recently found in compressed lithium (the lightest alkali element), probably arises from pressure-induced changes in the conduction-electron band structure. Superconductivity at ambient pressure in lithium has hitherto remained unresolved, both theoretically and experimentally. Here we demonstrate that lithium is a superconductor at ambient pressure with a transition temperature of 0.4 mK. As lithium has a particularly simple conduction electron system, it represents an important case for any attempts to classify superconductors and transition temperatures, especially to determine if any non-magnetic configuration can exclude superconductivity down to zero temperature. Furthermore, the combination of extremely weak superconductivity and relatively strong nuclear magnetism in lithium would clearly lead to mutual competition between these two ordering phenomena under suitably prepared conditions.
TL;DR: In this article, a series of Ni43Mn46−xCuxSn11 (x=1, 2, and 3) alloys was prepared by the arc melting method.
Abstract: A series of Ni43Mn46−xCuxSn11 (x=1, 2, and 3) alloys was prepared by the arc melting method. The martensitic transition shifts to a higher temperature with increasing Cu concentration. The isothermal magnetization curves around the martensitic transition temperature show a typical metamagnetic behavior. Under a low applied magnetic field of 10kOe, positive values of magnetic entropy change around the martensitic transition temperature are 14.1, 18.0, and 15.8J∕kgK for x=1, 2, and 3, respectively. While in the vicinity of the Curie temperature of the austenitic phase, these negative values are 1.1, 1.0, and 0.9J∕kgK for x=1, 2, and 3, respectively. The origin of the large entropy changes and the potential application for Ni43Mn46−xCuxSn11 alloys as a working substance for magnetic refrigeration are discussed.
TL;DR: High-temperature magnetization measurements showed that the ferromagnetic Curie temperature (T(M)) decreases with increasing Mn in PbMn(x)Ti(1-x)O(3).
Abstract: We report magnetoelectric coupling at room temperature between ferroelectric and magnetic order parameters in Mn-doped PbTiO3 compounds prepared by a solid-state reaction method. X-ray diffraction showed that PbMnxTi1?xO3 (x = 0.1, 0.3 and 0.5) compounds were single phase. The Mn substitution reduced the lattice distortion, i.e., the c/a ratio, and hence the ferroelectric Curie temperature (TC) decreased with increasing Mn content. High-temperature magnetization measurements showed that the ferromagnetic Curie temperature (TM) decreases with increasing Mn in PbMnxTi1?xO3. An anomaly in the dielectric constant (?) was observed in the vicinity of the ferromagnetic transition temperature. These samples exhibited magnetism and ferroelectricity simultaneously at room temperature, which was evidenced from the coexistence of saturated magnetization and polarization hysteresis loops. An enhancement in saturation polarization after poling the samples in the magnetic field was evidence of magnetoelectric coupling at room temperature. An enhancement of 11?13% in polarization was observed after poling the samples in a magnetic field at 1.2?T.