Khelifi Hedi | Faculty of Sciences of Sfax (original) (raw)
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National Institute of Technology, Tiruchirappalli
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A 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 ceramic is synthesized by conventional solid-state reaction method ... more A 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 ceramic is synthesized by conventional solid-state reaction method and investigated by structural, dielectric, thermal, Raman spectra and magnetization properties. The 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 is crystallized in rhombohedral distorted perovskite structure with space group R3c. The dielectric loss is investigated over wide range of temperature at 100 kHz. During its evolution, an anomaly is observed at 300 C which corresponds to TN (antiferromagnetic transition temperature). Besides, it is confirmed by DSC measurement. A magnetic property is confirmed by the temperature dependence of magnetization (M–T) under an applied magnetic field of 0.05 T. That revealed an antiferromagnetic transition of 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 ceramic. The latter confirms which was
previously mentioned. Furthermore, these results reveal considerable spectral changes in the vicinity of the Neel temperature TN. Finally, this shift is discussed through structural, dielectric, thermal, vibrational and magnetic combination near the TN phase.
Lead-free (1x)NaNbO 3 /xBa(Ti 0.5 Sn 0.5 )O 3 (x = 0.1, 0.125, 0.15, 0.175, 0.2, and 0.3) ceramic... more Lead-free (1x)NaNbO 3 /xBa(Ti 0.5 Sn 0.5 )O 3 (x = 0.1, 0.125, 0.15, 0.175, 0.2, and 0.3) ceramics were elaborated by the conventional ceramic technique. Sintering has been made at 1523 K for 2 h. The crystal structure was investigated by X-ray diffraction with CuKa radiation at room temperature. As a function of composition, these compounds crystallize with tetragonal or cubic symmetry. Dielectric measurements show that the materials have a classical ferroelectric behavior for compositions in the range 0.10 B x B 0.15 and relaxor one for compositions in the range 0.15 \ x B 0.30. Temperatures T C or T m decrease as x content increases. The ferroelectric behavior has been confirmed by hysteresis characterization. For x = 0.1, a piezoelectric coefficient d 31 of 42.146 pC N -1 was obtained at room temperature. The evolution of the Raman spectra was studied as a function of temperature for x = 0.1.
The polycrystalline samples of (1 À x)BiFeO 3 -xBa 0.8 Sr 0.2 TiO 3 (x = 0, 0.1, 0.2, 0.25, 0.3, ... more The polycrystalline samples of (1 À x)BiFeO 3 -xBa 0.8 Sr 0.2 TiO 3 (x = 0, 0.1, 0.2, 0.25, 0.3, 0.4 and x = 1) were prepared by the conventional solid state reaction method. The effect of substitution in BiFeO 3 by Ba 0.8 Sr 0.2 TiO 3 on the structural, dielectric and magnetic properties was investigated. X-ray diffraction study showed that these compounds crystallized at room temperature in the rhombohedral distorted perovskite structure for x 0.3 and in cubic one for x = 0.4. As Ba 0.8 Sr 0.2 TiO 3 content increases, the dielectric permittivity increases. This work suggests also that the Ba 0.8 Sr 0.2 TiO 3 substitution can enhance the magnetic response at room temperature. A remanent magnetization M r and a coercive magnetic field H C of about 0.971 emu/g and 2.616 kOe, respectively were obtained in specimen with composition x = 0.1 at room temperature. #
A 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 ceramic is synthesized by conventional solid-state reaction method ... more A 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 ceramic is synthesized by conventional solid-state reaction method and investigated by structural, dielectric, thermal, Raman spectra and magnetization properties. The 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 is crystallized in rhombohedral distorted perovskite structure with space group R3c. The dielectric loss is investigated over wide range of temperature at 100 kHz. During its evolution, an anomaly is observed at 300 C which corresponds to TN (antiferromagnetic transition temperature). Besides, it is confirmed by DSC measurement. A magnetic property is confirmed by the temperature dependence of magnetization (M–T) under an applied magnetic field of 0.05 T. That revealed an antiferromagnetic transition of 0.9BiFeO3–0.1Ba0.8Sr0.2TiO3 ceramic. The latter confirms which was
previously mentioned. Furthermore, these results reveal considerable spectral changes in the vicinity of the Neel temperature TN. Finally, this shift is discussed through structural, dielectric, thermal, vibrational and magnetic combination near the TN phase.
Lead-free (1x)NaNbO 3 /xBa(Ti 0.5 Sn 0.5 )O 3 (x = 0.1, 0.125, 0.15, 0.175, 0.2, and 0.3) ceramic... more Lead-free (1x)NaNbO 3 /xBa(Ti 0.5 Sn 0.5 )O 3 (x = 0.1, 0.125, 0.15, 0.175, 0.2, and 0.3) ceramics were elaborated by the conventional ceramic technique. Sintering has been made at 1523 K for 2 h. The crystal structure was investigated by X-ray diffraction with CuKa radiation at room temperature. As a function of composition, these compounds crystallize with tetragonal or cubic symmetry. Dielectric measurements show that the materials have a classical ferroelectric behavior for compositions in the range 0.10 B x B 0.15 and relaxor one for compositions in the range 0.15 \ x B 0.30. Temperatures T C or T m decrease as x content increases. The ferroelectric behavior has been confirmed by hysteresis characterization. For x = 0.1, a piezoelectric coefficient d 31 of 42.146 pC N -1 was obtained at room temperature. The evolution of the Raman spectra was studied as a function of temperature for x = 0.1.
The polycrystalline samples of (1 À x)BiFeO 3 -xBa 0.8 Sr 0.2 TiO 3 (x = 0, 0.1, 0.2, 0.25, 0.3, ... more The polycrystalline samples of (1 À x)BiFeO 3 -xBa 0.8 Sr 0.2 TiO 3 (x = 0, 0.1, 0.2, 0.25, 0.3, 0.4 and x = 1) were prepared by the conventional solid state reaction method. The effect of substitution in BiFeO 3 by Ba 0.8 Sr 0.2 TiO 3 on the structural, dielectric and magnetic properties was investigated. X-ray diffraction study showed that these compounds crystallized at room temperature in the rhombohedral distorted perovskite structure for x 0.3 and in cubic one for x = 0.4. As Ba 0.8 Sr 0.2 TiO 3 content increases, the dielectric permittivity increases. This work suggests also that the Ba 0.8 Sr 0.2 TiO 3 substitution can enhance the magnetic response at room temperature. A remanent magnetization M r and a coercive magnetic field H C of about 0.971 emu/g and 2.616 kOe, respectively were obtained in specimen with composition x = 0.1 at room temperature. #