Evolution of superconducting transition temperature (T{sub c}) upon intercalation of HgBr{sub 2} into the Bi{sub 2}Sr{sub 1.5-x}La{sub x}Ca{sub 1.5}Cu{sub 2}O{sub y}

Journal Article · Thu Feb 29 04:00:00 EST 1996 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp952748n· OSTI ID:226741

Choy, J H; Park, N G; Hwang, S J; Khim, Z G ^[1]

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1. Seoul National Univ. (Korea, Republic of)

Intercalation of HgBr{sub 2} into Bi{sub 2}Sr{sub 1.5-x}La{sub x}Ca{sub 1.5}Cu{sub 2}O{sub y} (0.0 <= x <= 0.4) superconductor has been carried out in order to elucidate the origin of T{sub c} evolution upon intercalation. The T{sub c}`s obtained from the dc magnetic susceptibility measurements were plotted against x. The plots of T{sub c} vs x for the pristines showed the parabolic feature with overdoped (0.0 <= x < 0.1), optimally doped (x = 0.1), and underdoped (0.2 <= x <= 0.4) regions. The T{sub c}`s of the HgBr{sub 2} intercalates in the overdoped region were reduced less than nearly 6 K but increased by 4-6 K in the underdoped one compared with nonintercalated samples. Such changes in T{sub c} upon intercalation indicate hole doping from intercalant to host lattice. An attempt of semiempirical calculation was made to determine the hole concentration doped by intercalation. Upon HgBr{sub 2} intercalation, the amount of hole doping was estimated to be nearly 0.2 hole per formula unit of the sample with x = 0.0, whereas the doping of nearly 0.3 hole was estimated for the iodine intercalated sample. Considering the T{sub c} depression ({Delta}T{sub c}) and lattice expansion ({Delta}d) between the iodine intercalate ({Delta}T{sub c} {approx} 10 K and {Delta}d {approx} 3.6 A) and the HgBr{sub 2} one ({Delta}T{sub c} {approx} 6 K and {Delta}d {approx} 6.3 A), it can be concluded that the change in T{sub c} upon intercalation clearly depends on the hole concentration due to the charge transfer between host and guest, rather than the interblock electronic coupling due to the lattice expansion. 28 refs., 10 figs.

• OSTI ID: 226741
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 9 Vol. 100; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
66 PHYSICS
ABUNDANCE
CLATHRATES
HOLES
MAGNETIC SUSCEPTIBILITY
MERCURY BROMIDES
STRUCTURAL CHEMICAL ANALYSIS
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION TEMPERATURE
X-RAY DIFFRACTION