Resistivity and magnetic susceptibility studies of Tl[sub m]Ca[sub n[minus]1]Ba[sub 2]Cu[sub n]O[sub y] before and after doping with LiF

Journal Article · Thu Apr 01 00:00:00 EST 1993 · Journal of Superconductivity; (United States)

DOI:https://doi.org/10.1007/BF00617810· OSTI ID:5607289

El-Hamalawy, A A; El-Zaidia, M M; Ammar, A A; Elkholy, M M ^[1]

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1. Menoufia Univ. (Egypt)

Measurements of the superconducting resistance as a function of temperature were performed using the conventional four-probe method. The transition to complete superconductivity was recorded for samples of (Tl[sub 2]Ca[sub 2]Ba[sub 2]Cu[sub 3]O[sub 10])[sub 100[minus]x]LiF[sub x] (2223) mixed with different LiF ratios x = 0, 2, 4, 5, 6, 8, 10, and 12wt.%. It was found that the transition temperature T[sub c] was increased up to 5 wt.% of LiF. Further addition of LiF decreases T[sub c]. Therefore, 5 wt.% LiF is the optimum concentration giving a transition temperature of 130 K. Measurements of the superconducting resistance of all the samples except the (1111) compound show that the addition of 5 wt.% LiF increases T[sub c] and decreases the metastable phases. The real part of the a.c. magnetic susceptibility [chi][sub a.c.] is studied using a zero-field cooled mechanism. The temperature dependence of [chi][sub a.c.] for the prepared TlBaCaCuO having stoichiometric composition of (1111), (2223), (2234), and (3245) and that after doping with 5 wt.% LiF showed a broad feature. The transition to the complete diamagnetic state takes place in a broad transition region containing many transition steps, indicating the presence of metastable phases. The addition of LiF decreases the fluctuation in the transition region and its effect in reducing the number of multiphases. 29 refs., 10 refs.

• OSTI ID: 5607289
• Journal Information: Journal of Superconductivity; (United States), Vol. 6:2; ISSN 0896-1107
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
CRYSTAL DOPING
ELECTRIC CONDUCTIVITY
MAGNETIC SUSCEPTIBILITY
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
COPPER COMPOUNDS
LITHIUM FLUORIDES
THALLIUM COMPOUNDS
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ELECTRICAL PROPERTIES
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
LITHIUM COMPOUNDS
LITHIUM HALIDES
MAGNETIC PROPERTIES
PHYSICAL PROPERTIES
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
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