Transcript Magnetism and Superconductivity

Summary of Materials Science Breakout Session
Current 5 year plan (Sonier)
1. A high field low temperature muSR
spectrometer (MacLaughlin and Kiefl)
2. Low energy muon beamline 1000 m+/s at
TRIUMF. (Morenzoni-PSI,
Bakule+Matsuda- RIKEN and Brewer)
3. Independent source of 8Li for beta-NMR
(MacFarlane and Morris)
Major components of
the last 5 year plan
(Sonier)
TRIUMF
$2.22M
CFI $2.4M +
Matching funds
M20
=$6M
mSR at 15T and 20 mK (MacLaughlin)
Existing Hightime spectrometer TRIUMF is 8T/2K=4T/K
B/T in New spectrometer ~200 times larger!
What is the interest in low T and high B ?
CMP is the study of the collective behaviour of electrons
Low T ground state and elementary excitations
High B/T  Zeeman energy>> kTnew ground states new properties
e.g. Field-Induced Superconductivity in URhGe
Lévy et al. 05
Detector arrangement (Kiefl)
Top view
77K
TM
L
4K
Cold finger
B=15T
m+
F
Veto
10 mm
Veto
R
sample
1.
2.
Split Solenoid 15T ~$1M
Cryostat inserts 2K, 300mK and 20 mK+ detectors ~$1M
Confinement another way to significantly alter
electronic and magnetic properties of electrons at
interfaces, near surfaces and thin films
(Morenzoni and MacFarlane)
A
B
t
LA
LB
Magnetic properties change as a function of thickness and depth
Morenzoni
G. Nieuwenhuys, E. Morenzoni, S. Vongtragool,
H. Luetkens, A. Suter, Th. Prokscha, F. Galli,
M. Hesselberth submitted to PRL 2007
LE muSR in Fe/Ag Magnetic Multilayers
H. Luetkens, J. Korecki, E. Morenzoni, T. Prokscha,
M. Birke, H. Glückler, R. Khasanov, H.-H. Klauss, T.
Slezak, A. Suter, E. M. Forgan, Ch. Niedermayer, and F.
J. Litterst
Phys Rev. Lett. 91, 017204 (2003).
Magnetic field distribution in Ag
4nm
20nm
4nm
LE muon Proposals at PSI in 2007
Morenzoni

Low-energy muon-spin-rotation studies on thin film multilayers consisting of cuprate
high-TC sc and FM oxides

Microscopic investigations of a metal-superconductor proximity bilayer

Motion and Pinning of hole-poor pockets in cuprates

Charge differentiation of positive muons in insulators and semiconductors at low
implantation energies

Magnetic and superconducting properties of electron-Doped La2-xCexCuO4 epitaxial
thin films

Conduction Electron Spin Polarization of the Nonmagnetic Layers of FM/NM
Heterostructures

Superconductivity and magnetism in YBa2Cu3O7/PrBa2Cu3O7/YBa2Cu3O7 tri-layers

Spin Freezing in underdoped HTS

Spin Coherent Transport in Organic Spin Valves

Studies of Polymer Surface Dynamics

Influence of electric fields on manganites studied by low-energy muon precession.

Study of Superconducting-Magnetic Coupling in Superconducting Spin Valve
Structures

Ferromagnetism in III-V and II-IV-V2 dilute magnetic semiconductors

Proximity effect in Pd/Fe bilayers and Fe/Pd/Fe trilayers.
LE muon proposals at PSI cont’d

Low energy µSR study of moving vortices in type-II superconductors.

Magnetic Penetration in a Superconducting Sandwich and Thin Film

Organic thin-films and solar cells

Investigation of magnetism in HfO2 and related systems

Induced ferromagnetism in superconducting layer of superconductor/ferromagnet
heterostructures

Low Energy MuSR Studies of Mn doped GaAs

Measurement of the Magnetic Properties of a mono-Layer of Single Molecule Magnets

Magnetism in Proton-Irradiated HOPG Carbon

A direct measurement of the interplay between ferromagnetism and superconductivity
at atomically flat oxide interfaces.

Spin-polarized injection from a magnetic semiconductor into a nonmagnetic
semiconductor: spintronics via μSR
MacFarlane
Structural phase near the surface of SrTiO3 at 150K
Salman et al. PRL 96, 147601 (2006)
Tc bulk
0.75
Implanted [%]
Normalized Polarization
1.00
0.50
0.25
3.0
2.0
1.0
0.0
0
2000
4000
Depth [Å ]
0
50
100
150
T [K]
200
250
300
Progress in βNMR
Project
Publications
High Spin Molecules on Surfaces Nano Letters (07)
Near Surface Vortex State of
NbSe2
Thin Metal Films
Phys Rev Lett, 98, 167001
(07)
Phys Rev Lett 98, 047601
(07)
Phys Rev B 75, 073405 (07)
Phys Rev Lett 93, 157601
(04)
Surface Effects on Phase
Transitions
Phys Rev Lett 96, 147601
(06)
7+ low energy expts,
6 w/ accelerated beam,
two RIB sources
ONE mass separator
Can’t make a big impact
3 weeks/year no good
Brewer
MESON HALL
BEAM DUMP
TNF
(moved)
150 µA beam dump
$$$
Low Energy µ+
Beam
“Dai Omega” style
High Flux Surface µ+ Beam
Surface Muon Source
Custom Production Target
in a “magnetic bottle” for pions
M20
“µSR
M9
T2
Ghetto”
150 µA
BL1
Conclusion
1. Independent source of 8Li for beta-NMR
at TNF or proton hall
2. A high field low temperature muSR
spectrometer. CFI +Japanese funding?
3. A low energy muon beamline with 1000
m+/s at the sample could probably be
made here at TRIUMF. However the
money might be better spent helping to
build a low energy muon at J-PARC.