arXiv subjects

V. Nagarajan

Publications and source records attributed to V. Nagarajan.

20 records · Page 2Linked to original sources

arXiv2003

Ferroelectric Nanotubes

We report the independent invention of ferroelectric nanotubes from groups in several countries. Devices have been made with three different materials: lead zirconate-titanate PbZr1-xTixO3 (PZT); barium titanate BaTiO3; and strontium bismuth tantalate SrBi2Ta2O9 (SBT). Several different deposition techniques have been used successfully, including misted CSD (chemical solution deposition) and pore wetting. Ferroelectric hysteresis and high optical nonlinearity have been demonstrated. The structures are analyzed via SEM, TEM, XRD, AFM (piezo-mode), and SHG. Applications to trenching in Si dynamic random access memories, ink-jet printers, and photonic devices are discussed. Ferroelectric filled pores as small as 20 nm in diameter have been studied.

cond-mat.mtrl-sci↗

arXiv1998

The magnetoresistance in GdNi: Magnetic-polaronic-like effect near Curie temperature and low temperature sign reversal

The results of magnetoresistance ($Δρ/ρ$)measurements in GdNi, in the temperature range 4.2 to 300 K are reported. The sign of $Δρ/ρ$ above the Curie temperature (Tc= 70 K) is negative and its magnitude in a magnetic field of 80kOe grows with decreasing temperature below 150 K with a peak value of about -20% at Tc. These features, qualitatively resembling those in giant magnetoresistance systems (manganates), are attributed to the formation of some kind of magnetic polarons induced by Gd. The magnetoresistance changes sign below 12 K which is attributed to subtle band structure effects.

cond-mat.str-el↗