Browsing by Subject "Scanning hall probes"

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Open Access
Bean-Livingston surface barriers for flux penetration in Bi 2Sr 2CaCu 2O 8+δ single crystals near the transition temperature
(2011) Mihalache V.; Dede, M.; Oral, A.; Miu L.
The first field for magnetic flux penetration H p in Bi 2Sr 2CaCu 2O 8+δ (Bi-2212) single crystals near the critical temperature T c was investigated from the local magnetic hysteresis loops registered for different magnetic field H sweeping rates by using a scanning Hall probe microscope (SHPM) with ∼1 μm effective spatial resolution. Evidences for a significant role of the surface barrier were obtained: the asymmetric shape of the magnetization loops and an anomalous change in the slope of H p(T) close to T c. © 2011 Elsevier B.V. All rights reserved.
Open Access
High sensitivity and multifunctional micro-Hall sensors fabricated using InAlSb/InAsSb/InAlSb heterostructures
(2009) Bando, M.; Ohashi, T.; Dede, M.; Akram, R.; Oral, A.; Park, S.Y.; Shibasaki I.; Handa H.; Sandhu, A.
Further diversification of Hall sensor technology requires development of materials with high electron mobility and an ultrathin conducting layer very close to the material's surface. Here, we describe the magnetoresistive properties of micro-Hall devices fabricated using InAlSb/InAsSb/InAlSb heterostructures where electrical conduction was confined to a 30 nm-InAsSb two-dimensional electron gas layer. The 300 K electron mobility and sheet carrier concentration were 36 500 cm2 V-1 s-1 and 2.5× 1011 cm-2, respectively. The maximum current-related sensitivity was 2 750 V A-1 T-1, which was about an order of magnitude greater than AlGaAs/InGaAs pseudomorphic heterostructures devices. Photolithography was used to fabricate 1 μm×1 μm Hall probes, which were installed into a scanning Hall probe microscope and used to image the surface of a hard disk. © 2009 American Institute of Physics.