RIKEN Accel. Prog. Rep. 48 (2015)

Ⅲ-2. Atomic & Solid State Physics (Muon)µSR study of the Al-induced magnetic order in La2−x2−xSrx
xCu1−y1−yAlyyO44
∗1,∗2
∗1,∗3
∗4
∗1
∗1
∗1K.
K. M.
M. Suzuki,
Suzuki,∗1,∗2T.
T. Adachi,
Adachi,∗1,∗3
M.
M. A.
A. Baqiya,
Baqiya,∗4
M.
M. Abdel-Jawad,
Abdel-Jawad,∗1
S.
S. Yoon,Yoon,∗1I.
I. Watanabe,
Watanabe,∗1andand∗1,∗4∗1,∗4Y.
Y. Koike
Koike

TheThe so-calledso-called stripe
stripe correlationcorrelation ofof spins
spins andand holes
holes
has
has been
been studiedstudied intensively
intensively inin orderorder toto clarify
clarify its
its rerelationshiplationship withwith thethe appearance
appearance ofof superconductivity
superconductivity
inin thethe high-T
high-Tcc cuprates.
cuprates. Nevertheless,
Nevertheless, thethe details
details ofof
thethe stripes
stripes have
have notnot yetyet been
been clariﬁed
clariﬁed toto date.
date. OneOneofof thethe reasonsreasons isis thatthat thethe frequencies
frequencies ofof thethe dynamdynamical
ical stripes
stripes areare fasterfaster than
than thethe µSRµSR frequency
frequency range
range
in
in aa wide
wide range
range ofof thethe hole-concentration
hole-concentration per
per Cu,Cu, p,p,
where
where thethe superconductivity
superconductivity appears.
appears. For
For this
this reareason,
son, impurity
impurity substitution
substitution isis oneone ofof crucial
crucial ways
ways toto
study
study thethe stripe
stripe correlation,correlation, because
because substituted
substituted imimpurities
purities tendtend toto slow
slow down
down thethe spin
spin ﬂuctuations,ﬂuctuations, leadleading
ing toto thethe formation
formation ofof thethe static
static stripe
stripe order.
order. ForFormerly,
merly, we
we havehave found
found fromfrom thethe zero-ﬁeld
zero-ﬁeld (ZF)
(ZF) µSR
µSR
3+
that
that thethe magnetic
magnetic impurity
impurity Fe
Fe3+
tends
tends toto stabilize
stabilize aa
magnetic
magnetic order
order inin thethe whole
whole superconducting
superconducting regime
regime ofof
1,2)
1,2)
LaLa2−xSrSrCu
CuFeFeOO(LSCFO).
(LSCFO).
Intriguing
Intriguing
isis
that
that
2−x xx1−y
1−y yy 44
doubledouble successive
successive magnetic
magnetic transitionstransitions areare observed
observed ininthethe overdoped
overdoped regime
regime ofof LSCFO,LSCFO, indicating
indicating thatthat thethestripe
stripe order
order induced
induced byby thethe Fe
Fe substitution
substitution persists
persists up
up
toto pp ∼∼ 0.30
0.30 andand terminatesterminates there.
there. As
As forfor eﬀects
eﬀects ofof nonnon2+
magnetic
magnetic Zn
Zn2+
substitution,substitution, weakness
weakness ofof thethe develpdevelpment
ment ofof thethe Cu-spin
Cu-spin correlation
correlation byby thethe ZnZn substitution
substitution
prevents
prevents us
us fromfrom understanding
understanding thethe nature
nature ofof thethe CuCu3)
spin
spin correlation
correlation especially
especially inin thethe overdoped
overdoped regime.
regime.3)
Recently,
Recently, we
we havehave observed
observed unexpected
unexpected behavior
behavior inin
3+
non-magnetic
non-magnetic Al
Al3+-substituted-substituted La
La2−xSrSrCuCuAlAlOO
2−x xx1−y
1−y yy 44(LSCAO)(LSCAO) by
by thethe µSRµSR measurements,measurements, namely,namely, aa static
staticmagnetic
magnetic state
state isis induced
induced byby 3%
3% Al-substitution
Al-substitution inin thetheoverdoped
overdoped regime.
regime. It
It is
is expected
expected thatthat eﬀects
eﬀects ofof nonnonmagnetic
magnetic impurities
impurities onon the
the Cu-spin
Cu-spin correlation
correlation willwill bebeclariﬁed
clariﬁed even
even inin thethe overdoped
overdoped regime.
regime.
Therefore,Therefore, inin orderorder toto investigate
investigate thethe magnetism
magnetism ininduced
duced byby thethe Al
Al substitution,
substitution, we
we havehave performed
performed ZFZFµSRµSR experiments
experiments forfor LSCAOLSCAO withwith xx == 0.11
0.11 –– 0.30
0.30 andandyy == 0.03.
0.03. The
The polycrystalline
polycrystalline samples
samples were
were preparedpreparedby
by thethe ordinary
ordinary solid-statesolid-state reaction
reaction method.
method. ZF-µSR
ZF-µSR
measurements
measurements werewere carried
carried out
out usingusing aa Variox,
Variox, aa HeHeliox
liox andand aa Janis
Janis cryostats
cryostats at
at temperaturestemperatures down
down toto 0.3
0.3
KK at
at RIKEN-RAL.
RIKEN-RAL.
FigureFigure 1(a)1(a) shows
shows thethe ZF-µSR
ZF-µSR timetime spectra
spectra ofofLSCAO
LSCAO withwith xx == 0.300.30 andand yy == 0.03.
0.03. AtAt 5.05.0 K,
K, thethespectral
spectral shows
shows thethe Gaussian-type
Gaussian-type relaxation
relaxation due
due toto thetherandomly-oriented
randomly-oriented nuclear
nuclear dipole
dipole ﬁeld,ﬁeld, indicating
indicating elecelectrontron spins
spins ﬂuctuate
ﬂuctuate fast
fast beyond
beyond thethe µSRµSR timetime window.
window.
WithWith decreasing
decreasing temperature,temperature, thethe muon-spinmuon-spin depolardepolarization
ization becomes
becomes fast
fast progressively
progressively down
down toto 0.80.8 K
K andandﬁnally
ﬁnally aa nearly-staticnearly-static magneticmagnetic order
order isis formed
formed at
at 0.30.3
K,K, suggestingsuggesting aa remarkableremarkable eﬀect
eﬀect ofof thethe Al-substitution
Al-substitutiononon thethe development
development ofof thethe Cu-spin
Cu-spin correlation
correlation even
even ininthethe heavily-doped
heavily-doped regime.
regime. Figure
Figure 1(b)1(b) shows
shows thethe pp dedependence
pendence ofof thethe magnetic
magnetic transitiontransition temperature,temperature, TTNN,,
deﬁneddeﬁned asas thethe midpoint
midpoint ofof thethe changechange inin thethe initial
initialasymmetryasymmetry ofof thethe magnetic
magnetic component
component inin an
an analyticalanalytical
function.
function. It
It is
is foundfound thatthat TTNN decreases
decreases monotoniously
monotoniously
withwith increasing
increasing p,p, suggestingsuggesting thatthat thethe stripe
stripe order
order isisinduced
induced also
also inin thethe overdoped
overdoped regime.
regime. Moreover,Moreover, TTNN
2)
disappears
disappears at
at pp ∼∼ 0.30
0.30 asas observed
observed inin LSCFOLSCFO2)andand3)3)
LSCZO.
LSCZO. Therefore,Therefore, it
it hashas been
been concluded
concluded that,
that, reregardlessgardless ofof thethe type
type ofof impurities,
impurities, thethe development
development
ofof thethe stripe
stripe correlation
correlation isis observed
observed up
up toto pp ∼∼ 0.30,0.30,
suggestingsuggesting an
an intimate
intimate relationshiprelationship between
between thethe stripe
stripecorrelation
correlation andand thethe appearance
appearance ofof thethe high-T
high-Tcc supersuperconductivity.
conductivity. Considering
Considering thethe diﬀerence
diﬀerence between
between thethe3+2+3+
results
results ofof Fe
Fe3+,, Zn
Zn2+andand Al
Al3+,, charge
charge disorderdisorder as
as wellwellas
as large
large magnetic
magnetic moments
moments may
may play
play anan important
important rolerole
inin thethe stabilization
stabilization ofof thethe stripe
stripe correlation.
correlation.

∗1∗1

References
References

∗2
∗2
∗3
∗3
∗4
∗4

RIKEN
RIKEN Nishina
Nishina CenterCenterInstituteInstitute forfor Materials
Materials Research,Research, TohokuTohoku University
University
Department
Department ofof Engineering
Engineering andand Applied
Applied Sciences,Sciences, Sophia
SophiaUniversityUniversity
Department
Department ofof Applied
Applied Physics,
Physics, Tohoku
Tohoku University
University

La
La2-x
SrxxCuCu1-y
AlyyO
O442-xSr
1-yAl
xx == 0.30,0.30, yy == 0.03
0.03

Normalized Asymmetry

1.0
1.0
0.8
0.8

5.0
5.0 K
K
3.0 K
K
3.0
1.5 K
K
1.5
1.2 K
K
1.2
0.8 K
K
0.8
0.3 K
K
0.3

0.6
0.6
0.4
0.4
0.2
0.20000

22TN (K)N88

446688TimeTime (µ(µµµsec)sec)

77

La
La2-x
SrxxCuCu1-y
AlyyO
O442-xSr1-yAl

66

yy == 0.03
0.031010554433
22110000

0.05
0.05

0.10
0.10

0.15
0.15

pp (( == xx -- y)y)

0.20
0.20

0.25
0.25

0.30
0.30

Fig.
Fig. 1.
1. (a)(a) Zero-field
Zero-field µSRµSR timetime spectra
spectra ofof La
La2−x
SrxxCu
Cu1−y
AlyyO
O44
2−xSr
1−yAl
(LSCAO)(LSCAO) withwith xx == 0.300.30 andand yy == 0.03.
0.03. (b)(b) Temperature
Temperaturedependence
dependence ofof thethe magnetic
magnetic transitiontransition temperature,temperature, TTNN,,
ofof LSCAO
LSCAO withwith yy == 0.03.
0.03.

1)
1) K.
K. M.
M. Suzuki
Suzuki etet al.,
al., Phys.
Phys. Rev.
Rev. B
B 86,86, 014522
014522 (2012).
(2012).
2)
2) K.
K. M.
M. Suzuki
Suzuki etet al.,
al., inin preparation.
preparation.
3)3) Risdiana,
Risdiana, etet al.,al., Phys.
Phys. Rev.
Rev. B
B 77,77, 054516
054516 (2008).
(2008).

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