Al-Mustansiriyah Journal of Science
ISSN: 1814-635X (print), ISSN:2521-3520 (online)
Volume 29, Issue 2, 2018 DOI: http://doi.org/10.23851/mjs.v29i2.301
169
Copyright © 2017 Authors and Al-Mustansiriyah Journal of Science. This work is licensed under a Creative Commons
Attribution-NonCommercial 4.0 International License.
Research Article Open Access
Effect of α-TeO
2
Substitution on Hg - System Properties
Shatha H. Mahdi*
Department of Physics, College of Education for Pure Science (Ibn Al Haitham),
University of Baghdad, IRAQ.
*Author email: shatha246@yahoo.com
A r t i c l e I n f o Abstract
Submitted
01/11/2017
Accepted
26/11/2017
Specimens of HgBa
2-x
Te
x
Ca
2
Cu
3
O
8+
with x =0, 0.15, 0.3 and 0.45, were prepared by
traditional method (SSR). The results showed enhancing structural and electrical (resistivity
vs temperature) properties, where XRD analysis shows a tetragonal structure for all specimens
and high ratio of Hg-1223 phase with an increase of the lattice parameter and T
c,
except
x=0.45, it shown semiconductor. The HgBa
1.70
Te
0.30
Ca
2
Cu
3
O
8+
specimen with x= 0.3 shows
the highest (T
c
=143K) than with T
c
of the basic compound HgBa
2
Ca
2
Cu
3
O
8+
equal (135K), at
increment of Te content. While mechanical properties have been weakened as consequence to
increasing brittleness of HgBa
2-x
Te
x
Ca
2
Cu
3
O
8+
compounds at increment Te content
Keywords: HgBa
2-x
Te
x
Ca
2
Cu
3
O
8+
compound; brittleness; Ba–Te substitution.
خلصـة ال
تم تحضيرلعينات اHgBa
2-x
Te
x
Ca
2
Cu
3
O
8+
بالطريقةديةتقلي ال( تفاعللحالة اصلبة الSSR .) اظهرتلنتائج ا تحسن
الخواص التركيبية ولكهربائية ا( تغيرقاومية الم مع درجةارة الحر) ، حيث اظهرت نتائج حيود الشعة السينية ان التركيب
لسائد ا هولرباعي اكل ل النسبعدا ما نسبة0.45 فإنه يظهر تركيب شبه موصل. تبين العينةHgBa
1.70
Te
0.30
Ca
2
Cu
3
O
8+
( x=0.3 ) لها اعلىنتقال ا( T
c
=143K ) مقارنة مع المركباس السHgBa
2
Ca
2
Cu
3
O
8+
(135K) عند زيادة
محتوىTe . بينما ضعفتائص الخصلميكانيكية ا لمركبHgBa
2-x
Te
x
Ca
2
Cu
3
O
8+
نتيجةزدياد ااشة الهش مع زيادة
محتوىTe .
Introduction
In 1993, the family of the Hg-based (HTC)
superconductor was discovered by Putilin et al
[1-3]. It consists crystalline structures of the
Hg-system layers are insulating block [BaO -
HgO – BaO] with a thickness of 0.55 nm, and
[(CuO
2
) + Ca (n - 1)] conducting blocks [0.4 +
0.32 (n - 1)] nm [4-6], as shown in Figure
(1)[7].
Figure 1: crystal structure of the Hg-[1212][7]
The HBCCO system, contain multi phases of
the homologous series HgBa
2
Ca
n−1
Cu
n
O
2n+2+δ
where n (CuO
2
layers) = 1, 2, 3, 4, 5, which
yields 94, 104 and 130 K superconducting
phases, respectively. Figure 2 [8] shows, in
depending on layers of CuO
2
, the unit cell has
single [Hg-2201], double [Hg -1212] and triple
[Hg-1223] phases respectively [9, 10].
Figure 2: Crystal structure of the Hg [12(n-1)n]-system,
at(n = 1, 2, 3)[8].