The magnetic properties of Metallo-organic heterostructure interfaces are studied. These heterostructures are built with manganese phthalocyanine (MnPc) and iron phthalocyanine (FePc). Previously, the powder of each material is reported to be an Ising-like chain magnet with Arrhenius relaxation. The relaxation is slow enough to exhibit magnetic hysteresis at low temperatures. Each layer of the heterostructure is investigated separately by depositing a thin film of either iron phthalocyanine (FePc) or manganese phthalocyanine (MnPc) on a Silicon substrate heated to 150 °C. FePc thin films show magnetic hysteresis below 5K with a typical coercivity of 1850 ± 50 Oe and moment of about 1.9 µB in agreement with values from the literature. Similarly, the MnPc thin film deposited at 150 °C shows magnetic hysteresis at 2.5 K, and no hysteresis at 5K and 10 K. A coercive field of 390 Oe is recorded at 2.5 K. The saturation magnetization is near 9 emu cm–3, which corresponds to an effective magnetic moment per Mn ion of about 0.5 µB. For the MnPc/FePc thin film bilayer, the FePc is deposited at 150 °C onto the Silicon substrate, the sample is cooled to room temperature followed by the MnPc deposition in situ. The magnetic moment of this heterostructure is consistent with contributions from the FePc layer only, since the room temperature deposited MnPc has antiferromagnetic characteristics. This heterostructure has magnetic hysteresis with a coercivity of 910 Oe. No measurable shift of the hysteresis loops—as expected for an antiferromagnetic-ferromagnetic coupled interface—is observed in this set of bilayers.
|Commitee:||Ojeda-Aristizabal, Claudia, Peterson, Michael R.|
|School:||California State University, Long Beach|
|Department:||Physics and Astronomy|
|School Location:||United States -- California|
|Source:||MAI 57/02M(E), Masters Abstracts International|
|Subjects:||Physics, Condensed matter physics, Materials science|
|Keywords:||Exchange bias, Iron phthalocyanine, Manganese phthalocyanine, Organic molecules, Semiconductors|
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