Superconductivity in Y-Ba-Cu-Ag-O and Y-Ba-Cu-Pt-O Systems

A STUDY OF THE Y-Ba-Cu-Ag-O SYSTEM: The specimens studied were produced using the standard ceramic technique. High purity source materials Y2O3, BaCO3CuO, and Ag2O were used. Solid state synthesis was carried out at 900 C for six hours in oxygen ambient. Pressed samples of 16 mm diameter and 2 mm thick were processed in an atmosphere of pure oxygen at 950 C for 12 hours. The transition temperature to the superconducting state was measured by the four point probe resistance technique. The ac magnetic susceptibility was determined by the method outlined in [1].

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IMPACT OF Zn SUBSTITUTION ON PHASE FORMATION AND SUPERCONDUCTIVITY OF Bi1.6Pb0.4Sr2Ca2Cu3-xZnxO10-δ WITH x = 0.0, 0.015, 0.03, 0.06, 0.09 AND 0.12

Modern Physics Letters B ◽

10.1142/s0217984905008785 ◽

2005 ◽

Vol 19 (16) ◽

pp. 771-778 ◽

Cited By ~ 1

Author(s):

R. B. SAXENA ◽

RAJIV GIRI ◽

V. P. S. AWANA ◽

H. K. SINGH ◽

M. A. ANSARI ◽

...

Keyword(s):

Magnetic Susceptibility ◽

Transition Temperature ◽

Lattice Parameter ◽

Ac Magnetic Susceptibility ◽

Critical Transition ◽

Critical Transition Temperature ◽

Reaction Route ◽

Zn Doping ◽

Zn Substitution ◽

Solid State Reaction Route

Samples of series Bi 1.6 Pb 0.4 Sr 2 Ca 2 Cu 3-x Zn x O 10-δ with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12 are synthesized by solid-state reaction route. All the samples crystallize in tetragonal structure with majority (> 90%) of Bi -2223( Bi 2 Sr 2 Ca 2 Cu 3 O 10) phase (c-lattice parameter ~ 36 Å). The proportion of Bi -2223 phase decreases slightly with an increase in x. The lattice parameters a and c of main phase ( Bi -2223) do not change significantly with increasing x. Superconducting critical transition temperature (Tc) decreases with x as evidenced by both resistivity [ρ(T)] and ac magnetic susceptibility [χ(T)] measurements. Interestingly the decrement of Tc is not monotonic and the same saturates at around 96 K for x > 0.06. In fact Tc decreases fast (~ 10 K/at%) for x = 0.015 and 0.03 samples and later nearly saturates for higher x values. Present results of Zn doping in Bi -2223 system are compared with other Zn -doped HTSC (high temperature superconducting) systems, namely the RE -123 ( REBa 2 Cu 3 O 7) and La -214 (( La, Sr )2 CuO 4).

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Synthesis of calcium aluminates through the polymeric precursor route

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq0602137g ◽

2006 ◽

Vol 12 (2) ◽

pp. 137-140 ◽

Cited By ~ 4

Author(s):

A. Gaki ◽

R. Chrysafi ◽

Th. Perraki ◽

G. Kakali

Keyword(s):

Solid State ◽

High Purity ◽

Pechini Method ◽

Solid State Synthesis ◽

Polymeric Precursor ◽

Secondary Phases ◽

Calcium Aluminates ◽

Polycrystalline Ceramics ◽

Precursor Route

The Pechini method is a polymeric precursor route for the synthesis of polycrystalline ceramics of high purity. The conventional solid state synthesis of calcium aluminate compounds requires long-term lasting sintering at high temperatures. In this study, the Pechini method was applied for the preparation of pure CaO.Al2O3 and 3CaO.Al2O3. Solid state synthesis was also used in order to compare the final products obtained by the two methods. The intermediate and final products obtained were characterized by XRD and FTIR spectroscopy. It was concluded that the Pechini method can be successfully applied for the preparation of high purity CaO.Al2O3 and 3CaO.Al2O3. The formation of 3CaO.Al2O3 and CaO.Al2O3 requires three-hour sintering at 1000?C and 900?C, respectively. The main intermediate product was 5CaO.3Al2O3 in the case of 3CaO.Al2O3, while in the case of CaO.Al2O3 there were no other crystalline intermediate products. The samples prepared through solid state synthesis, contain a considerable amount of secondary phases, even after sintering at 1350-1400?C for more than 15 hours.

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High-Purity FeSe1−x Superconductors Prepared by Solid-State Synthesis and Liquid Phase Processing

Journal of the American Ceramic Society ◽

10.1111/j.1551-2916.2010.03912.x ◽

2010 ◽

Vol 93 (10) ◽

pp. 3195-3200 ◽

Cited By ~ 4

Author(s):

Xiaoding Qi ◽

Jiun-Yi Wang ◽

Chi-Jung Hung ◽

Jui-Chao Kuo ◽

Karen Yates ◽

...

Keyword(s):

Solid State ◽

Liquid Phase ◽

High Purity ◽

Solid State Synthesis

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AC magnetic susceptibility measurements near the superconducting transition temperature of YBCO sintered samples

Physica C Superconductivity ◽

10.1016/0921-4534(94)91135-5 ◽

1994 ◽

Vol 235-240 ◽

pp. 3217-3218 ◽

Cited By ~ 4

Author(s):

M. Polichetti ◽

S. Pace ◽

A. Saggese ◽

A.M. Testa ◽

C. Federico ◽

...

Keyword(s):

Magnetic Susceptibility ◽

Transition Temperature ◽

Superconducting Transition Temperature ◽

Superconducting Transition ◽

Ac Magnetic Susceptibility

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Oxygen Isotope Effect in Layered Manganites

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.152-153.116 ◽

2009 ◽

Vol 152-153 ◽

pp. 116-119

Author(s):

A.N. Taldenkov ◽

N.A. Babushkina ◽

A.V. Inyushkin ◽

R. Suryanarayanan

Keyword(s):

Magnetic Field ◽

Magnetic Susceptibility ◽

Transition Temperature ◽

Oxygen Isotope ◽

Isotope Effect ◽

Applied Magnetic Field ◽

Substantial Decrease ◽

Ac Magnetic Susceptibility ◽

Isotope Substitution ◽

Dc Magnetization

The oxygen isotope effect in ceramic bilayer manganite (La1 zPrz)1.2Sr1.8Mn216 18O7 (z = 0, 0.3, 0.4, 0.6) has been investigated. Real and imaginary parts of ac magnetic susceptibility, dc magnetization and magnetoresistance were measured at temperatures from 4.2 to 320 K in applied magnetic field up to 40 kOe. Substantial decrease of ferromagnetic (FM) transition temperature TFM under oxygen isotope substitution 16O → 18O was found. This positive isotope effect amounts to more than 20 K. A number of additional transitions of ferromagnetic type were observed at T >170 K, which also depend on oxygen overall mass. The obtained results are compared with those observed in other manganites exhibiting the large isotope effect.

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A Novel Family of Triangular CoII2LnIII and CoII2YIII Clusters by the Employment of Di-2-Pyridyl Ketone

Magnetochemistry ◽

10.3390/magnetochemistry5020035 ◽

2019 ◽

Vol 5 (2) ◽

pp. 35 ◽

Cited By ~ 2

Author(s):

Constantinos G. Efthymiou ◽

Áine Ní Fhuaráin ◽

Júlia Mayans ◽

Anastasios Tasiopoulos ◽

Spyros P. Perlepes ◽

...

Keyword(s):

Magnetic Susceptibility ◽

Solid State ◽

Structural Characterization ◽

Metal Clusters ◽

Variable Temperature ◽

Ac Susceptibility ◽

Exchange Interactions ◽

Ac Magnetic Susceptibility ◽

Ferromagnetic Exchange ◽

Weak Ferromagnetic

The synthesis, structural characterization and magnetic study of novel CoII/4f and CoII/YIII clusters are described. In particular, the initial employment of di-2-pyridyl ketone, (py)2CO, in mixed metal Co/4f chemistry, provided access to four triangular clusters, [CoII2MIII{(py)2C(OEt)(O)}4(NO3)(H2O)]2[M(NO3)5](ClO4)2 (M = Gd, 1; Dy, 2; Tb, 3; Y, 4), where (py)2C(OEt)(O)− is the monoanion of the hemiketal form of (py)2CO. Clusters 1–4 are the first reported Co/4f (1–3) and Co/Y (4) species bearing (py)2CO or its derivatives, despite the fact that over 200 metal clusters bearing this ligand have been reported so far. Variable-temperature, solid-state dc and ac magnetic susceptibility studies were carried out on 1–4 and revealed the presence of weak ferromagnetic exchange interactions between the metal ions (JCo-Co = +1.3 and +0.40 cm−1 in 1 and 4, respectively; JCo-Gd = +0.09 cm−1 in 1). The ac susceptibility studies on 2 revealed nonzero, weak out-of-phase (χ’’M) signals below ~5 K.

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