Structural transition and magnetic properties of high Cr-doped BiFeO3 ceramic

Abstract

Magnetic properties of BiFe1-xCrxO3 perovskite-type solids reaction synthesized at high pressure were investigated and a magnetic phase diagram was established. X-ray diffraction data revealed a crystal structure transformation from rhombohedral to monoclinic as Cr3+ ions substituted Fe ions in the samples. Néel temperature TN and spin-reorientation temperature TSR were determined from dM/dT by measuring the temperature dependence of magnetization (M-T). The magnetization results indicated that TN and TSR were strongly dependent on Cr3+ ion doping; both TN and TSR decreased with the increase of Cr3+ doping. The magnetic hysteresis loops investigated at room temperature reflected an antiferromagnetic behavior from x= 0.4 to 0.6 and weak ferromagnetic at x=1.0. Besides, the remnant magnetization Mr and maximum magnetization Mmax increased with increasing x from 0.4 up to 1.0. The Cr doping was found to be helpful in reducing coercivity Hc for the magnetic samples from x= 0.4 to 0.8 and their applications as magnetic sensors are possible.

Magnetic Behaviour of Perovskite Compositions Derived from BiFeO3

“…In addition to the transition at Tm, the magnetic measurements of the BiFe1−yScyO3 samples with compositions 0.10 ≤ y ≤ 0.30 revealed some anomalies in the M(T) dependences at Ta (Tm < Ta < TN) that were also associated with the transitions between different AFM states [26]. As seen from Figure 4, no clear evidence of the AFM-AFM phase transformation (at Tm and/or Ta) in BiFe1−y[Zn0.5Ti0.5]yO3 can be found for the compositions with [39], Mn [12], Cr [29], Sc [26] and Zn 0.5 Ti 0.5 (this work). A suggested T N (y) behaviour for the (1−y)BiFeO 3 -yBiCoO 3 perovskites is shown with the dashed line.…”

“…Surprisingly, in the case of the iron-to-scandium substitution [26], magnetic ordering still remains at y = 0.60. The Néel temperature as a function of y for the BiFe1−yB 3+ yO3 perovskites with B 3+ = Co [39], Mn [12], Cr [29], Sc [26] and Zn0.5Ti0.5 (this work). A suggested TN(y) behaviour for the (1−y)BiFeO3-yBiCoO3 perovskites is shown with the dashed line.…”

“…Figure 7.The Néel temperature as a function of y for the BiFe1−yB 3+ yO3 perovskites with B 3+ = Co[39], Mn[12], Cr[29], Sc[26] and Zn0.5Ti0.5 (this work). A suggested TN(y) behaviour for the (1−y)BiFeO3-yBiCoO3 perovskites is shown with the dashed line.…”

“…Although a number of the BiFe 1−y B 3+ y O 3 perovskite series has already been prepared and characterized [11][12][13][14][15][16][17][18][19][20][21]28,29], to the best of our knowledge, the obtained structural and magnetic data have not been generalized in respect of the ionic size of the substituting cation. This is certainly worthy of consideration as the comparative studies of the variation of structural characteristics and transition temperatures in solid solutions and series the isomorphous substitutions of are known to be very convenient to understand some features and predict properties of new compositions [30].…”

Structural, Dielectric, Electrical, and Magnetic Characteristics of Bi0.8Ba0.1Er0.1Fe0.96Cr0.02Mn0.02O3 Nanoparticles

“…Figure 4a presents the magnetic hysteresis loops of the BBEFCMO nanoparticles in an applied field in the range of −10 T to 10 T, measured at 7 K and 300 K. The magnetization data displayed a significant hysteresis loop, indicating finite values for both coercive and remanent magnetization (M S ), and importantly an unsaturated magnetization under high fields. The unsaturated behavior indicates an antiferromagnetic (AFM) behavior [48][49][50]. Moreover, the important remanent magnetization value (nonzero), below which the magnetization sharply increased, serves as evidence for the presence of a ferromagnetic (FM) contribution presence within the compound [51].…”