We report the use of unshielded planar low- dc SQUIDs for temperature-dependent ac and dc magnetic susceptibility measurements on small particles in magnetic fields of up to 300 G. These measurements were made with integrated microsusceptometers which can operate in such fields when applied in the plane of the device. We show paramagnetic, antiferromagnetic, and superconducting behavior on various samples of order 20–50 μm from 0.3 to 4 K and discuss the effect of sample placement on the magnitude of the signal.
REFERENCES
1.
D. D.
Awschalom
, D. P.
DiVincenzo
, and J. F.
Smyth
, Science
258
, 414
(1992
).2.
D. D.
Awschalom
and J.
Warnock
, IEEE J. Quantum Electron.
25
, 2570
(1989
).3.
N. Q.
Fan
, M. B.
Heaney
, J.
Clarke
, D.
Newitt
, L. L.
Wald
, E. L.
Hahn
, A.
Bielecki
, and A.
Pines
, IEEE Trans. Magn.
MAG-25
, 1193
(1989
).4.
L. R.
Narasimhan
, M.
Takigawa
, and M. B.
Ketchen
, Appl. Phys. Lett.
65
, 1305
(1994
).5.
M. B.
Ketchen
, D.
Pearson
, A. W.
Kleinsasser
, C.-K.
Hu
, M.
Smyth
, J.
Logan
, K.
Stawiasz
, E.
Baran
, M.
Jaso
, T.
Toss
, K.
Petrillo
, M.
Manny
, S.
Basavaiah
, S.
Brodsky
, S. B.
Kaplan
, and W. J.
Gallagher
, Appl. Phys. Lett.
59
, 2609
(1991
).6.
K.
Stawiasz
, M. B.
Ketchen
, and L. R.
Narasimhan
, IEEE Trans. Appl. Supercond.
5
, 3230
(1995
).7.
D. D.
Awschalom
, J. R.
Rozen
, M. B.
Ketchen
, W. J.
Gallagher
, A. W.
Kleinsasser
, R. L.
Sandstrom
, and B.
Bumble
, Appl. Phys. Lett.
53
, 2108
(1988
).8.
M. B.
Ketchen
and J.
Kirtley
, IEEE Trans. Appl. Supercond.
5
, 2133
(1995
).9.
A. T.
Skjeltorp
, C. A.
Catanese
, H. E.
Meissner
, and W. P.
Wolf
, Phys. Rev. B
7
, 2062
(1973
).10.
M. J.
Ferrari
, M.
Johnson
, F. C.
Wellstood
, J.
Clarke
, P. A.
Rosenthal
, R. A.
Hammond
, and M. R.
Beasley
, Appl. Phys. Lett.
53
, 695
(1988
).
This content is only available via PDF.
© 1998 American Institute of Physics.
1998
American Institute of Physics
You do not currently have access to this content.
