Polaronic transport in the ferromagnetic phase of Gd1−xCaxBaCo2O5.53

  title={Polaronic transport in the ferromagnetic phase of Gd1−xCaxBaCo2O5.53},
  author={N. Thirumurugan and C. S. Sundar and Arvind Krishnasamy Bharathi},
  journal={Solid State Communications},
Abstract Temperature dependent electrical resistivity and thermopower measurements were carried out on Gd 1− x Ca x BaCo 2 O 5.53 with x varying between 0 and 0.25. Ca substitution leads to the incorporation of holes (Co 4+ ) into the system that leads to a reduction in resistivity and a stabilisation of the ferromagnetic phase at low temperatures. The temperature dependence of resistivity and thermopower are markedly different in the Ca doped sample, with a dramatic reduction in the… 
Magnetisation studies of phase co-existence in Gd1 − xCaxBaCo2O5.5
Abstract Magnetic properties of hole doped, oxygen deficient double perovskite compounds, Gd1 − xCaxBaCo2O5.5, have been investigated. Ferromagnetic transition temperatures increase and the
Tunable resistivity in magnetic glass phase of Gd(1-x)Ca(x)BaCo2O5.5.
We present magnetization and resistance measurements carried out on pristine and Ca-doped Gd(1-x)Ca(x)BaCo2O5.5 (x = 0.02) samples using the cooling and heating in unequal field (CHUF) protocol. The
Magnetocaloric effect in polycrystalline Gd1 − xCaxBaCo2O5.5
Abstract Calculations of the magnetocaloric effect had been carried out. Dependence of the magnetization on temperature variation for Gd 1 − x Ca x BaCo 2 O 5.5 upon 100 Oe magnetic fields was
High temperature magnetic and transport properties of PrBaCo2O6– cobaltite: Spin blockade evidence
Abstract The experimental data are presented for magnetic susceptibility and electrical conductivity in PrBaCo 2 O 6– δ at 850–1223 K. The decrease of oxygen content at heating is accompanied by
Effect of the Al-doping on the electrical and thermoelectric response of TbMnO3 polycrystalline samples: Evidence of polaronic transport
Abstract High-quality, polycrystalline Tb1−xAlxMnO3 (x = 0–0.2) samples were prepared by means of standard solid state reaction. The incorporation of the Al ions into the TbMnO3 lattice is verified
Tuning the electrical and optical properties of Gd1-xCaxBaCo2O5+δ (x = 0–0.5) using solar energy
Abstract This study reveals that the use of a Ca dopant can increase the solar absorption of GdBaCo 2 O 5+δ , with an optimal composition of Gd 0.8 Ca 0.2 BaCo 2 O 5 achieving 85% solar absorptance.
Chapter 1 Phase transitions in double perovskite GdBaCo 2 O 5
  • 2018
The present thesis is focussed mainly on the oxygen deficient layered double perovskite GdBaCo2O5+δ. To set the stage for the contents of the thesis, in this chapter, an overview of the description
Role of the Al-doping and epitaxial strain in the multiferroic behavior of TbMnO3 bulk and thin films
The Ph.D. thesis reports on the experimental investigation of the structure and physical properties of the perovskite-type multiferroic TbMnO3 when doped with aluminum ions in different atomic
Synthesis and conductivity properties of Gd0.8Ca0.2BaCo2O5+δ double perovskite by sol–gel combustion
Double perovskite oxides Gd0.8Ca0.2BaCo2O5+δ have been successfully prepared by EDTA-citrate complexation process. The prepared samples were characterized by means of thermogravimetry–differential
Influence of annealing atmosphere on the electrical and spectral properties of Gd0.8Ca0.2BaCo2O5+δ ceramic
For practical applications, the stability of perovskite-like oxides in various environments should be evaluated. In this work, samples of Gd0.8Ca0.2BaCo2O5+δ (GCBC2)were annealed in different


Ce-substitution effects in GdBaCo2O5+δ
Abstract Resistivity, thermopower, magnetoresistance and magnetic susceptibility investigations of Ce-substituted GdBaCo2O5+δ have been carried out in the temperature range 4.2–300 K. Ce substitution
Sr2+ doping effects on the transport and magnetic properties of GdBaCo2O5+δ
Studies on some new members of the cobalt perovskite Gd1−xSrxBaCo2O5+δ with low strontium concentrations (0<x<0.1) have been carried out with the aim of investigating possible metallization of the
Magnetic phase evolution in Fe substituted GdBaCo2O5.5
Abstract Magnetization and magneto-resistance experiments have been carried out on well characterized samples of the GdBaCo 2− x Fe x O 5.5 series. Zero field cooled magnetization measurements in the
Electron-hole asymmetry in GdBaCo2O(5+x): evidence for spin blockade of electron transport in a correlated electron system.
Doping asymmetry in the behavior of holes and electrons doped into a parent insulator GdBaCo2O(5.5) single crystals reveals that the doped holes greatly improve the conductivity, while the electron-doped samples always remain poorly conducting.
Thermoelectric power of HoBaCo2O5.5: possible evidence of the spin blockade in cobaltites.
Thermoelectric power measurements have been performed for an ordered oxygen-deficient perovskite, HoBaCo2O5.5, in which the alternative layers of CoO6 octahedra and of [CoO(5)](2) bipyramids are
Transport and magnetic properties of GdBaCo2O5+x single crystals : A cobalt oxide with square-lattice CoO2 planes over a wide range of electron and hole doping
Single crystals of the layered perovskite GdBaCo_{2}O_{5+x} (GBCO) have been grown by the floating-zone method, and their transport, magnetic, and structural properties have been studied in detail
Relevance of solid solution randomness for long-range phase separation in highly correlated oxides
We have studied the role of the intrinsic disorder, introduced by the presence of two different cations at the same crystallographic position, for promoting phase separation in highly correlated
Dynamical disorder of spin-induced Jahn-Teller orbitals with the insulator-metal transition in cobaltites.
The authors' pair density function analysis indicates that, in the paramagnetic insulating phase for all x, spin activation of Co3+ ions induces local static Jahn-Teller (JT) distortions, which coincides with narrowing of variant Planck's constant over 2 pi omega=22 and 24 meV modes in the phonon spectrum.
Oxygen content determination in perovskite-type cobaltates
Three oxygen content determination methods (iodometric titration, gas volumetric analysis and thermogravimetric hydrogen reduction) have been evaluated for the case of rare earth cobaltates LnBCo{sub
Magnetic and transport behavior of Ni-substitutedGdBaCo2O5+δperovskite
Electrical resistivity, dc magnetization, ac susceptibility, thermopower, and magnetoresistance measurements have been carried out on Ni-substituted