Asad Niazi - Academia.edu (original) (raw)

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Papers by Asad Niazi

Research paper thumbnail of Magnetic anomalies in the spin-chain systemSr3Cu1−xZnxIrO6

Research paper thumbnail of Superparamagnetic-like ac susceptibility behavior in the partially disordered antiferromagnetic compoundCa3CoRhO6

Research paper thumbnail of Sr3CuIrO6, a spin-chain compound with random ferromagnetic–antiferromagnetic interactions

Solid State Communications, 2001

Research paper thumbnail of The growth of a single crystal of Sr3CuIrO6 and its magnetic behavior compared to polycrystals

Pramana, 2002

We have grown single crystals of the psuedo-one-dimensional compound Sr 3 CuIrO 6 , a K 4 CdCl 6-... more We have grown single crystals of the psuedo-one-dimensional compound Sr 3 CuIrO 6 , a K 4 CdCl 6-derived monoclinic structure with Cu-Ir chains along the [101] direction. We present the ac and dc magnetization behavior of the single crystals in comparison with that of the polycrystalline form reported earlier. There is a distinct evidence for at least two magnetic transitions, at 5 K (T 1) and 19 K (T 2), with different relative magnitudes in the single and polycrystals. The low temperature magnetic relaxation behavior of both the forms is found to be widely different, exhibiting unexpected time dependence.

Research paper thumbnail of Inhomogeneous Magnetism in Single CrystallineSr3CuIrO6+δ: Implications to Phase-Separation Concepts

Physical Review Letters, 2002

Research paper thumbnail of Magnetic characteristics of Sr3Cu1−xZnxIrO6, a spin-chain system with competing interactions

Physica B: Condensed Matter, 2002

We report the results of AC and DC magnetization (1.8-300 K) measurements on the solid solution, ... more We report the results of AC and DC magnetization (1.8-300 K) measurements on the solid solution, Sr 3 Cu 1Àx Zn x IrO 6 ; forming in pseudo-one-dimensional K 4 CdCl 6-derived structure. Our results establish that the Cu end member is not a ferromagnet in zero magnetic field in sharp contrast to the belief in the literature, but appears to be a system in which both ferromagnetic and antiferromagnetic interactions compete; however, an application of a magnetic field of 1 kOe stabilizes the ferromagnetic state. The Zn-end member is an antiferromagnet below 19 K: Small substitutions at the Cu or Zn site significantly depress magnetic ordering temperature.

Research paper thumbnail of Evidence for the coexistence of low-dimensional magnetism and long-range order in Ca 3 CoRhO 6

Europhysics Letters (EPL), 2003

We report the results of neutron powder diffraction studies on the spin-chain compound Ca3CoRhO6 ... more We report the results of neutron powder diffraction studies on the spin-chain compound Ca3CoRhO6 in the temperature range 3 to 293 K. Bragg peaks due to magnetic ordering start appearing below about 100 K. The most interesting observation is that there is a diffuse magnetic peak superimposed over the strongest magnetic Bragg peak. The diffuse magnetic intensity is observed below as well above 100 K. This finding provides a new insight into the physics of this compound as though the low-dimensional magnetic interaction coexists with long range magnetic order-a novel situation among quasi one-dimensional oxides.

Research paper thumbnail of Magnetic anomalies in the spin-chain systemSr3Cu1−xZnxIrO6

Research paper thumbnail of Superparamagnetic-like ac susceptibility behavior in the partially disordered antiferromagnetic compoundCa3CoRhO6

Research paper thumbnail of Sr3CuIrO6, a spin-chain compound with random ferromagnetic–antiferromagnetic interactions

Solid State Communications, 2001

Research paper thumbnail of The growth of a single crystal of Sr3CuIrO6 and its magnetic behavior compared to polycrystals

Pramana, 2002

We have grown single crystals of the psuedo-one-dimensional compound Sr 3 CuIrO 6 , a K 4 CdCl 6-... more We have grown single crystals of the psuedo-one-dimensional compound Sr 3 CuIrO 6 , a K 4 CdCl 6-derived monoclinic structure with Cu-Ir chains along the [101] direction. We present the ac and dc magnetization behavior of the single crystals in comparison with that of the polycrystalline form reported earlier. There is a distinct evidence for at least two magnetic transitions, at 5 K (T 1) and 19 K (T 2), with different relative magnitudes in the single and polycrystals. The low temperature magnetic relaxation behavior of both the forms is found to be widely different, exhibiting unexpected time dependence.

Research paper thumbnail of Inhomogeneous Magnetism in Single CrystallineSr3CuIrO6+δ: Implications to Phase-Separation Concepts

Physical Review Letters, 2002

Research paper thumbnail of Magnetic characteristics of Sr3Cu1−xZnxIrO6, a spin-chain system with competing interactions

Physica B: Condensed Matter, 2002

We report the results of AC and DC magnetization (1.8-300 K) measurements on the solid solution, ... more We report the results of AC and DC magnetization (1.8-300 K) measurements on the solid solution, Sr 3 Cu 1Àx Zn x IrO 6 ; forming in pseudo-one-dimensional K 4 CdCl 6-derived structure. Our results establish that the Cu end member is not a ferromagnet in zero magnetic field in sharp contrast to the belief in the literature, but appears to be a system in which both ferromagnetic and antiferromagnetic interactions compete; however, an application of a magnetic field of 1 kOe stabilizes the ferromagnetic state. The Zn-end member is an antiferromagnet below 19 K: Small substitutions at the Cu or Zn site significantly depress magnetic ordering temperature.

Research paper thumbnail of Evidence for the coexistence of low-dimensional magnetism and long-range order in Ca 3 CoRhO 6

Europhysics Letters (EPL), 2003

We report the results of neutron powder diffraction studies on the spin-chain compound Ca3CoRhO6 ... more We report the results of neutron powder diffraction studies on the spin-chain compound Ca3CoRhO6 in the temperature range 3 to 293 K. Bragg peaks due to magnetic ordering start appearing below about 100 K. The most interesting observation is that there is a diffuse magnetic peak superimposed over the strongest magnetic Bragg peak. The diffuse magnetic intensity is observed below as well above 100 K. This finding provides a new insight into the physics of this compound as though the low-dimensional magnetic interaction coexists with long range magnetic order-a novel situation among quasi one-dimensional oxides.

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