Characterization of Phases in Duplex Stainless Steel by Magnetic Force Microscopy/Scanning Kelvin Probe Force Microscopy

2008 ◽  
Vol 11 (7) ◽  
pp. C41 ◽  
Author(s):  
Namurata Sathirachinda ◽  
Rolf Gubner ◽  
Jinshan Pan ◽  
Ulf Kivisäkk
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Kelvin Probe Force Microscopy ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Scanning Kelvin Probe

Scanning Kelvin Probe Force Microscopy Study of Hydrogen Distribution and Evolution in Duplex Stainless Steel

2017 ◽  
Author(s):  
Bai An ◽  
Zhengli Hua ◽  
Takashi Iijima ◽  
Chaohua Gu ◽  
Jinyang Zheng ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Kelvin Probe Force Microscopy ◽  
Kelvin Probe ◽  
Hydrogen Distribution ◽  
Force Microscopy ◽  
Hydrogen Charging ◽  
Scanning Kelvin Probe ◽  
The Difference ◽  
Two Phases

Detecting hydrogen distribution at micro- and nano-scale is important for understanding the mechanisms of hydrogen embrittlement in metals. In this study, scanning Kelvin probe force microscopy (SKPFM), which can detect the variation of surface contact potential difference (CPD) caused by hydrogen, is applied to investigate the hydrogen distribution and evolution in thermally hydrogen-charged (HC) super duplex stainless steel. The SKPFM observations reveal that the CPD distribution becomes nonuniform in both the ferrite and austenite phases after hydrogen charging, implying that hydrogen distributes heterogeneously in the two phases. The average CPDs of both the ferrite and austenite phases are significantly decreased and the difference of CPD between two phases reaches a maximum shortly after thermal hydrogen-charging. The average CPDs of both the ferrite and austenite phases recover and the difference of CPD between two phases is decreased upon release of the hydrogen. These results are discussed in terms of the hydrogen outgasing behavior and the difference of hydrogen diffusivity in the two phases.

scholarly journals Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination

2011 ◽  
Vol 2 ◽  
pp. 552-560 ◽  
Author(s):  
Miriam Jaafar ◽  
Oscar Iglesias-Freire ◽  
Luis Serrano-Ramón ◽  
Manuel Ricardo Ibarra ◽  
Jose Maria de Teresa ◽  
...  
Keyword(s):  
Long Range ◽  
Electrostatic Interaction ◽  
Electrostatic Interactions ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Superparamagnetic Nanoparticles ◽  
Kelvin Probe Force Microscopy ◽  
Magnetic Interactions ◽  
Kelvin Probe ◽  
Force Microscopy

The most outstanding feature of scanning force microscopy (SFM) is its capability to detect various different short and long range interactions. In particular, magnetic force microscopy (MFM) is used to characterize the domain configuration in ferromagnetic materials such as thin films grown by physical techniques or ferromagnetic nanostructures. It is a usual procedure to separate the topography and the magnetic signal by scanning at a lift distance of 25–50 nm such that the long range tip–sample interactions dominate. Nowadays, MFM is becoming a valuable technique to detect weak magnetic fields arising from low dimensional complex systems such as organic nanomagnets, superparamagnetic nanoparticles, carbon-based materials, etc. In all these cases, the magnetic nanocomponents and the substrate supporting them present quite different electronic behavior, i.e., they exhibit large surface potential differences causing heterogeneous electrostatic interaction between the tip and the sample that could be interpreted as a magnetic interaction. To distinguish clearly the origin of the tip–sample forces we propose to use a combination of Kelvin probe force microscopy (KPFM) and MFM. The KPFM technique allows us to compensate in real time the electrostatic forces between the tip and the sample by minimizing the electrostatic contribution to the frequency shift signal. This is a great challenge in samples with low magnetic moment. In this work we studied an array of Co nanostructures that exhibit high electrostatic interaction with the MFM tip. Thanks to the use of the KPFM/MFM system we were able to separate the electric and magnetic interactions between the tip and the sample.

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