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Magnetic properties of solid solutions between BiCrO 3 and BiGaO 3 with perovskite structures

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ABSTRACT

Magnetic properties of BiCr1−xGaxO3 perovskite-type solid solutions are reported, and a magnetic phase diagram is established. As-synthesized BiCrO3 and BiCr0.9Ga0.1O3 crystallize in a monoclinic (m) C2/c structure. The Néel temperature (TN) decreases from 111 K in BiCrO3 to 98 K in BiCr0.9Ga0.1O3, and spin-reorientation transition temperature increases from 72 K in BiCrO3 to 83 K in BiCr0.9Ga0.1O3. o-BiCr0.9Ga0.1O3 with a PbZrO3-type orthorhombic structure is obtained by heating m-BiCr0.9Ga0.1O3 up to 573 K in air; it shows similar magnetic properties with those of m-BiCr0.9Ga0.1O3. TN of BiCr0.8Ga0.2O3 is 81 K, and TN of BiCr0.7Ga0.3O3 is 63 K. Samples with x = 0.4, 0.5, 0.6 and 0.7 crystallize in a polar R3c structure. Long-range antiferromagnetic order with weak ferromagnetism is observed below TN = 56 K in BiCr0.6Ga0.4O3, TN = 36 K in BiCr0.5Ga0.5O3 and TN = 18 K in BiCr0.4Ga0.6O3. BiCr0.3Ga0.7O3 shows a paramagnetic behaviour because the Cr concentration is below the percolation threshold of 31%.

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Magnetic phase diagram of BiCr1−xGaxO3. TN is the Néel temperature, TSR is temperature of a spin-reorientation transition, PM is a paramagnetic phase and c-AFM is a canted antiferromagnetic phase.
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Figure 11: Magnetic phase diagram of BiCr1−xGaxO3. TN is the Néel temperature, TSR is temperature of a spin-reorientation transition, PM is a paramagnetic phase and c-AFM is a canted antiferromagnetic phase.

Mentions: The resulting magnetic phase diagram of BiCr1−xGaxO3 is given in figure 11. The TN gradually decreases with increasing x, as one would expect because of the dilution of the magnetic sublattice by a nonmagnetic ion, while TSR increases. By the extrapolation, the TN and TSR should merge near x = 0.15. There is almost linear dependence of TN on x in the compositional ranges of 0.0 ≤ x ≤ 0.3 and 0.4 ≤ x ≤ 0.7. In both ranges, TN vanishes near x = 0.7 by the extrapolation, that is, near the percolation threshold. From the extrapolation, we can also estimate that TN should be about 130 K for a hypothetical R3c phase of BiCrO3, which was studied theoretically in some papers [16, 25]; the theoretically estimated TN is about 80–120 K [25]. The G-type AFM structure should realize in BiCrO3-based perovskites as predicted in many theoretical papers [15, 16, 25] and found experimentally [11–13]. However, spin canting mechanisms might be different depending on the symmetry; this is why different regions are marked as c-AFM1, c-AFM2 and c-AFM3 in figure 11. Spin canting is allowed by the symmetry in the C2/c and R3c structures and G-type magnetic arrangements.


Magnetic properties of solid solutions between BiCrO 3 and BiGaO 3 with perovskite structures
Magnetic phase diagram of BiCr1−xGaxO3. TN is the Néel temperature, TSR is temperature of a spin-reorientation transition, PM is a paramagnetic phase and c-AFM is a canted antiferromagnetic phase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036460&req=5

Figure 11: Magnetic phase diagram of BiCr1−xGaxO3. TN is the Néel temperature, TSR is temperature of a spin-reorientation transition, PM is a paramagnetic phase and c-AFM is a canted antiferromagnetic phase.
Mentions: The resulting magnetic phase diagram of BiCr1−xGaxO3 is given in figure 11. The TN gradually decreases with increasing x, as one would expect because of the dilution of the magnetic sublattice by a nonmagnetic ion, while TSR increases. By the extrapolation, the TN and TSR should merge near x = 0.15. There is almost linear dependence of TN on x in the compositional ranges of 0.0 ≤ x ≤ 0.3 and 0.4 ≤ x ≤ 0.7. In both ranges, TN vanishes near x = 0.7 by the extrapolation, that is, near the percolation threshold. From the extrapolation, we can also estimate that TN should be about 130 K for a hypothetical R3c phase of BiCrO3, which was studied theoretically in some papers [16, 25]; the theoretically estimated TN is about 80–120 K [25]. The G-type AFM structure should realize in BiCrO3-based perovskites as predicted in many theoretical papers [15, 16, 25] and found experimentally [11–13]. However, spin canting mechanisms might be different depending on the symmetry; this is why different regions are marked as c-AFM1, c-AFM2 and c-AFM3 in figure 11. Spin canting is allowed by the symmetry in the C2/c and R3c structures and G-type magnetic arrangements.

View Article: PubMed Central - PubMed

ABSTRACT

Magnetic properties of BiCr1−xGaxO3 perovskite-type solid solutions are reported, and a magnetic phase diagram is established. As-synthesized BiCrO3 and BiCr0.9Ga0.1O3 crystallize in a monoclinic (m) C2/c structure. The Néel temperature (TN) decreases from 111 K in BiCrO3 to 98 K in BiCr0.9Ga0.1O3, and spin-reorientation transition temperature increases from 72 K in BiCrO3 to 83 K in BiCr0.9Ga0.1O3. o-BiCr0.9Ga0.1O3 with a PbZrO3-type orthorhombic structure is obtained by heating m-BiCr0.9Ga0.1O3 up to 573 K in air; it shows similar magnetic properties with those of m-BiCr0.9Ga0.1O3. TN of BiCr0.8Ga0.2O3 is 81 K, and TN of BiCr0.7Ga0.3O3 is 63 K. Samples with x = 0.4, 0.5, 0.6 and 0.7 crystallize in a polar R3c structure. Long-range antiferromagnetic order with weak ferromagnetism is observed below TN = 56 K in BiCr0.6Ga0.4O3, TN = 36 K in BiCr0.5Ga0.5O3 and TN = 18 K in BiCr0.4Ga0.6O3. BiCr0.3Ga0.7O3 shows a paramagnetic behaviour because the Cr concentration is below the percolation threshold of 31%.

No MeSH data available.