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Title: Scanning Hall Probe Imaging of ErNi2B2C

Abstract

We report scanning Hall probe imaging of ErNi{sub 2}B{sub 2}C in the superconducting, antiferromagnetic, and weakly ferromagnetic regimes in magnetic fields up to 20 Oe, well below H{sub c1}, with two results. First, imaging isolated vortices shows that they spontaneously rearrange on cooling through the antiferromagnetic transition temperature T{sub N} = 6 K to pin on twin boundaries, forming a striped pattern. Second, a weak, random magnetic signal appears in the ferromagnetic phase below T{sub WFM} = 2.3 K, and no spontaneous vortex lattice is present down to 1.9 K. We conclude that ferromagnetism coexists with superconductivity either by forming small ferromagnetic domains or with oscillatory variation of the magnetization on sub-penetration depth length scales.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
877526
Report Number(s):
SLAC-PUB-11576
TRN: US200608%%65
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; FERROMAGNETISM; PROBES; SUPERCONDUCTIVITY; TRANSITION TEMPERATURE; ERBIUM CARBIDES; NICKEL CARBIDES; ERBIUM BORIDES; NICKEL BORIDES; HALL EFFECT; Other,MATSCI

Citation Formats

Bluhm, Hendrik, Sebastian, Suchitra, Guikema, Janice W., Fisher, I.R., Moler, Kathryn A., and /Stanford U., Appl. Phys. Dept.. Scanning Hall Probe Imaging of ErNi2B2C. United States: N. p., 2005. Web.
Bluhm, Hendrik, Sebastian, Suchitra, Guikema, Janice W., Fisher, I.R., Moler, Kathryn A., & /Stanford U., Appl. Phys. Dept.. Scanning Hall Probe Imaging of ErNi2B2C. United States.
Bluhm, Hendrik, Sebastian, Suchitra, Guikema, Janice W., Fisher, I.R., Moler, Kathryn A., and /Stanford U., Appl. Phys. Dept.. Fri . "Scanning Hall Probe Imaging of ErNi2B2C". United States. doi:. https://www.osti.gov/servlets/purl/877526.
@article{osti_877526,
title = {Scanning Hall Probe Imaging of ErNi2B2C},
author = {Bluhm, Hendrik and Sebastian, Suchitra and Guikema, Janice W. and Fisher, I.R. and Moler, Kathryn A. and /Stanford U., Appl. Phys. Dept.},
abstractNote = {We report scanning Hall probe imaging of ErNi{sub 2}B{sub 2}C in the superconducting, antiferromagnetic, and weakly ferromagnetic regimes in magnetic fields up to 20 Oe, well below H{sub c1}, with two results. First, imaging isolated vortices shows that they spontaneously rearrange on cooling through the antiferromagnetic transition temperature T{sub N} = 6 K to pin on twin boundaries, forming a striped pattern. Second, a weak, random magnetic signal appears in the ferromagnetic phase below T{sub WFM} = 2.3 K, and no spontaneous vortex lattice is present down to 1.9 K. We conclude that ferromagnetism coexists with superconductivity either by forming small ferromagnetic domains or with oscillatory variation of the magnetization on sub-penetration depth length scales.},
doi = {},
journal = {Physical Review B},
number = ,
volume = ,
place = {United States},
year = {Fri Dec 02 00:00:00 EST 2005},
month = {Fri Dec 02 00:00:00 EST 2005}
}
  • The authors have used a low noise Scanning Hall Probe Microscope (SHPM) to study vortex structures in superconducting films. The microscope has high magnetic field ({approximately}2.9 x 10{sup {minus}8}T/{radical}Hz at 77K) and spatial resolution, {approximately}0.85 {mu}m. Magnetic field profiles of single vortices in High T{sub c} YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films have been successfully measured and the microscopic penetration depth of the superconductor has been extracted as a function of temperature. Flux penetration into the superconductor has been imaged in real time ({approximately}8s/frame).
  • We present the design, construction, and performance of a low-temperature scanning Hall probe microscope with submicron lateral resolution and a large scanning range. The detachable microscope head is mounted on the cold flange of a commercial {sup 3}He-refrigerator (Oxford Instruments, Heliox VT-50) and operates between room temperature and 300 mK. It is fitted with a three-axis slip-stick nanopositioner that enables precise in situ adjustment of the probe location within a 6x6x7 mm{sup 3} space. The local magnetic induction at the sample surface is mapped with an easily changeable microfabricated Hall probe [typically GsAs/AlGaAs or AlGaAs/InGaAs/GaAs Hall sensors with integrated scanningmore » tunnel microscopy (STM) tunneling tips] and can achieve minimum detectable fields {>=}10 mG/Hz{sup 1/2}. The Hall probe is brought into very close proximity to the sample surface by sensing and controlling tunnel currents at the integrated STM tip. The instrument is capable of simultaneous tunneling and Hall signal acquisition in surface-tracking mode. We illustrate the potential of the system with images of superconducting vortices at the surface of a Nb thin film down to 372 mK, and also of labyrinth magnetic-domain patterns of an yttrium iron garnet film captured at room temperature.« less
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  • We describe results from a scanning Hall probe microscope operating in a broad temperature range, 4{endash}300 K. A submicron Hall probe manufactured in a GaAs/AlGaAs two-dimensional electron gas is scanned over the sample to measure the surface magnetic fields using conventional scanning tunneling microscopy positioning techniques. The magnetic field structure of the sample together with the topography can be obtained simultaneously. The technique is noninvasive with an extremely low self-field of {lt}10{sup {minus}2} G and yields a quantitative measurement of the surface magnetic field in contrast to magnetic force microscopy. In addition the microscope has an outstanding magnetic field resolutionmore » ({approximately}1.1{times}10{sup {minus}3} G/{radical}Hz at 77 K) and high spatial resolution, {approximately}0.85 {mu}m. Images of individual vortices in a high-{ital T}{sub {ital c}} Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin film at low temperatures and magnetic domains in an Fe-garnet crystal at room temperature are presented. {copyright} {ital 1996 American Vacuum Society}« less
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