Gas-phase synthesis and magnetism of HfO2 nanoclusters

• Published in: The European physical journal. D, Atomic, molecular, and optical physics Atomic, molecular, and optical physics, 2013-02, Vol.67 (2), Article 42
• Main Authors: Lin, Kang-Qi, Wang, Lai-Sen, Wang, Zhen-Wei, Wen, Rui-Tao, Chen, Yuanzhi, Peng, Dong-Liang
• Format: Article
• Language: English
• Subjects: Applications of Nonlinear Dynamics and Chaos Theory; Atomic; Atomic and molecular clusters; Atomic and molecular physics; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Molecular; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Optical and Plasma Physics; Physical Chemistry; Physics; Physics and Astronomy; Quantum Information Technology; Quantum Physics; Regular Article; Spectroscopy/Spectrometry; Spintronics; Studies of special atoms, molecules and their ions; clusters; Topical issue: ISSPIC 16 - 16th International Symposium on Small Particles and Inorganic Clusters
• ISSN: 1434-6060; 1434-6079
• DOI: 10.1140/epjd/e2013-30524-9

Since the unexpected room-temperature ferromagnetism was found in undoped HfO 2 thin film, the origin of ferromagnetism became a debatable research hotspot The HfO 2 nanostructure materials prepared by traditional synthetic methods usually shows monoclinic phase. In this work, tetragonal phase HfO 2 nanoclusters (NCs) with uniform morphology and diameters ranging from 7 to 12 nm were prepared via plasma gas condensation cluster beam deposition technique. By annealing at 300, 600, 800 °C in air and Ar(95%) + H 2 (5%) for 3 h, respectively, the HfO 2 NCs gradually transformed from tetragonal phase into monoclinic phase. The magnetic measurement results showed that as-prepared HfO 2 NCs with either tetragonal or monoclinic phase were paramagnetic, which is different from the diamagnetic behavior of bulk HfO 2 and is also not in agreement with ferromagnetism reported in some other works.