Scanning SQUID microscope differentiation of ferromagnetic steelphases

Journal Article · Wed Sep 01 00:00:00 EDT 1999 · Acta Materialia

OSTI ID:894383

Shaw, T J; Chan, J W; Kang, S -H; McDermott, R; Morris, Jr, J W; Clarke, John

We have studies the remanent magnetization of ferromagneticsteel with five different microstructures using a microscope based on ahigh-transition-temperature dc Superconducting QUantum InterferenceDevice (SQUID). We prepared the samples using different heat treatments,beginning with the same material composition. We magnetized each samplein turn in a magnetic field of 50 mT, and studied the remanentmagnetization by scanning the sample over the SQUID using atwo-dimensional (2D) translation stage with a range of 50 mm X 50 mm.With a sample-to-SQUID separation of 400-500(mu)m, this procedure yieldeda 2D magnetic field image produced by the local remanent magnetization ofthe sample. In addition, we have obtained microstructural informationusing optical imaging, allowing us to correlate the magnetic images withthe underlying microstructure.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of Basic EnergySciences. Division of Materials Sciences
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 894383
• Report Number(s): LBNL--44248
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 10 Vol. 48
• Country of Publication: United States
• Language: English

Related Subjects

non-destructive evaluation steels magnetic methods SQUIDoptical microscopy