کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1624368 | 1516419 | 2008 | 7 صفحه PDF | دانلود رایگان |
A detailed study of step-like metamagnetic transitions in polycrystalline Pr0.75Na0.25Mn1 − xFexO3 (0 ≤ x ≤ 0.30) is reported. It shows that the charge-orbit ordering antiferromagnetic (COOAF) phase in the phase-separated materials is responsible for the step-like metamagnetic transition with extremely sharp steps (width <0.01 T). The fraction of antiferromagnet II (AFII) with larger antiferromagnetic exchange interaction than COOAF is proved to be the effective factor of critical fields (Hc). A model of anisotropy barrier for up/down thermal blocking spins has been proposed to explain the sharp step-like transitions in polycrystalline manganites for the first time. The metamagnetic transitions at 2 K (below the spin blocking temperature TB) and high temperatures are compared. Both sorts of metamagnetic transitions originate from COOAF phase. And the temperature is responsible for the difference between them.
Journal: Journal of Alloys and Compounds - Volume 458, Issues 1–2, 30 June 2008, Pages 11–17