Electrical, magnetic and magnetotransport properties of Na and Mo doped Ca3Co4O9 materials

Uzma Hira, Jean-Claude Grivel, Dennis Valbjørn Christensen, Nini Pryds, Falak Sher*

*Corresponding author for this work

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Abstract

We report the electrical, magnetic and magnetotransport properties of Na and Mo dual doped Ca3-2xNa2xCo4-xMoxO9 (0 ≤ x ≤ 0.15) polycrystalline samples. The results indicate that the strength of ferrimagnetic interaction decreases with increase in doping, as is evident from the observed decrease in Curie temperatures (TC). The substitution of non-magnetic Mo6+ ions (4d0) in CoO2 layers and the presence of oxygen vacancies are responsible for decrease in ligand field strength, which results in an enhanced magnetization in the low doped x = 0.025 sample due to a change from the low spin to partial high spin electron configuration. The electrical resistivity of samples exhibits a semiconducting-like behavior in the low temperature range, a strongly correlated Fermi liquid-like behavior in the intermediate temperature range, and an incoherent metal-like behavior in the temperature range 210-300 K. All the samples show a large negative magnetoresistance (MR) at low temperature with a maximum MR value of -59% for the x = 0.025 sample at 2 K and 16 T applied field. The MR values follow the observed trend in magnetization at 5 K and sharply increase below the Curie temperatures of the samples, suggesting that the ferrimagnetic interactions are mainly responsible for the decrease in electrical resistivity under an applied magnetic field.
Original languageEnglish
JournalRSC Advances
Volume9
Issue number54
Pages (from-to)31274-31283
Number of pages10
ISSN2046-2069
DOIs
Publication statusPublished - 2019

Cite this

@article{c6d83b3e9a424d1cb70a0578d0c20397,
title = "Electrical, magnetic and magnetotransport properties of Na and Mo doped Ca3Co4O9 materials",
abstract = "We report the electrical, magnetic and magnetotransport properties of Na and Mo dual doped Ca3-2xNa2xCo4-xMoxO9 (0 ≤ x ≤ 0.15) polycrystalline samples. The results indicate that the strength of ferrimagnetic interaction decreases with increase in doping, as is evident from the observed decrease in Curie temperatures (TC). The substitution of non-magnetic Mo6+ ions (4d0) in CoO2 layers and the presence of oxygen vacancies are responsible for decrease in ligand field strength, which results in an enhanced magnetization in the low doped x = 0.025 sample due to a change from the low spin to partial high spin electron configuration. The electrical resistivity of samples exhibits a semiconducting-like behavior in the low temperature range, a strongly correlated Fermi liquid-like behavior in the intermediate temperature range, and an incoherent metal-like behavior in the temperature range 210-300 K. All the samples show a large negative magnetoresistance (MR) at low temperature with a maximum MR value of -59{\%} for the x = 0.025 sample at 2 K and 16 T applied field. The MR values follow the observed trend in magnetization at 5 K and sharply increase below the Curie temperatures of the samples, suggesting that the ferrimagnetic interactions are mainly responsible for the decrease in electrical resistivity under an applied magnetic field.",
author = "Uzma Hira and Jean-Claude Grivel and Christensen, {Dennis Valbj{\o}rn} and Nini Pryds and Falak Sher",
year = "2019",
doi = "10.1039/c9ra06110j",
language = "English",
volume = "9",
pages = "31274--31283",
journal = "R S C Advances",
issn = "2046-2069",
publisher = "RSC Publishing",
number = "54",

}

Electrical, magnetic and magnetotransport properties of Na and Mo doped Ca3Co4O9 materials. / Hira, Uzma; Grivel, Jean-Claude; Christensen, Dennis Valbjørn; Pryds, Nini; Sher, Falak.

In: RSC Advances, Vol. 9, No. 54, 2019, p. 31274-31283.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Electrical, magnetic and magnetotransport properties of Na and Mo doped Ca3Co4O9 materials

AU - Hira, Uzma

AU - Grivel, Jean-Claude

AU - Christensen, Dennis Valbjørn

AU - Pryds, Nini

AU - Sher, Falak

PY - 2019

Y1 - 2019

N2 - We report the electrical, magnetic and magnetotransport properties of Na and Mo dual doped Ca3-2xNa2xCo4-xMoxO9 (0 ≤ x ≤ 0.15) polycrystalline samples. The results indicate that the strength of ferrimagnetic interaction decreases with increase in doping, as is evident from the observed decrease in Curie temperatures (TC). The substitution of non-magnetic Mo6+ ions (4d0) in CoO2 layers and the presence of oxygen vacancies are responsible for decrease in ligand field strength, which results in an enhanced magnetization in the low doped x = 0.025 sample due to a change from the low spin to partial high spin electron configuration. The electrical resistivity of samples exhibits a semiconducting-like behavior in the low temperature range, a strongly correlated Fermi liquid-like behavior in the intermediate temperature range, and an incoherent metal-like behavior in the temperature range 210-300 K. All the samples show a large negative magnetoresistance (MR) at low temperature with a maximum MR value of -59% for the x = 0.025 sample at 2 K and 16 T applied field. The MR values follow the observed trend in magnetization at 5 K and sharply increase below the Curie temperatures of the samples, suggesting that the ferrimagnetic interactions are mainly responsible for the decrease in electrical resistivity under an applied magnetic field.

AB - We report the electrical, magnetic and magnetotransport properties of Na and Mo dual doped Ca3-2xNa2xCo4-xMoxO9 (0 ≤ x ≤ 0.15) polycrystalline samples. The results indicate that the strength of ferrimagnetic interaction decreases with increase in doping, as is evident from the observed decrease in Curie temperatures (TC). The substitution of non-magnetic Mo6+ ions (4d0) in CoO2 layers and the presence of oxygen vacancies are responsible for decrease in ligand field strength, which results in an enhanced magnetization in the low doped x = 0.025 sample due to a change from the low spin to partial high spin electron configuration. The electrical resistivity of samples exhibits a semiconducting-like behavior in the low temperature range, a strongly correlated Fermi liquid-like behavior in the intermediate temperature range, and an incoherent metal-like behavior in the temperature range 210-300 K. All the samples show a large negative magnetoresistance (MR) at low temperature with a maximum MR value of -59% for the x = 0.025 sample at 2 K and 16 T applied field. The MR values follow the observed trend in magnetization at 5 K and sharply increase below the Curie temperatures of the samples, suggesting that the ferrimagnetic interactions are mainly responsible for the decrease in electrical resistivity under an applied magnetic field.

U2 - 10.1039/c9ra06110j

DO - 10.1039/c9ra06110j

M3 - Journal article

VL - 9

SP - 31274

EP - 31283

JO - R S C Advances

JF - R S C Advances

SN - 2046-2069

IS - 54

ER -