Magnetic and transport properties of delafossite oxides <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si9.gif" overflow="scroll"><mml:msub><mml:mrow><mml:mi>CuCr</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mo>-</mml:mo><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mi>Mg</mml:mi><mml:mo>,</mml:mo><mml:mi>Ca</mml:mi><mml:msub><mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub><mml:msub><mml:mro

Okuda, Takashi; Onoe, T.; Beppu, Y.; Terada, Norio; Doi, Toshiya; Miyasaka, S.; Tokura, Y.

doi:10.1016/j.jmmm.2006.10.1141

Cited by 30 publications

(14 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4 showing linear behaviors for the ln(q/T) = f(T À1 ) and ln(q) = f(T À1 ) curves of CuCr 0.98 Mg 0.02 O 2 and CuCrO 2 , respectively. It must be pointed out that the mechanism responsible for the electrical transport in the CuCr 1Àx Mg x O 2 series is a matter of debate, 5,9,10 as some authors proposed conduction via the Cu network, according to the Cu 2+ /Cu + mixed-valency created by the Mg 2+ substitution for Cr 3+ , while others suggested conduction by Cr 4+ /Cr 3+ mixed valency. In this respect, our recent electronic band calculations point towards exclusive participation of the Cr 3+ t 2g orbitals at the Fermi level.…”

Section: P-type Oxides: Delafossitesmentioning

confidence: 99%

Thermoelectric Oxides: Effect of Doping in Delafossites and Zinc Oxide

Guilmeau

Maignan

Martin

2009

Journal of Elec Materi

View full text Add to dashboard Cite

The electrical resistivity (q) and Seebeck coefficient (S) of the three delafossites CuFe 0.9 Cr 0.1 O 2 , CuCr 0.98 Mg 0.02 O 2 , and CuRh 0.9 Mg 0.1 O 2 have been measured and their power factor (PF) calculated. These p-type oxides show PF values at 800 K from 1.4 9 10 À4 W K À2 m À1 to 6.9 9 10 À4 W K À2 m À1 . In contrast to delafossites containing Fe or Cr, for which q exhibits a dq dT < 1 regime, the Rh-based delafossite shows a metallic regime from 5 K to 1000 K. This points toward the role of the transition-metal electronic configuration in the transport properties. Otherwise, similar PF values are obtained in the case of the n-type Al-doped ZnO. For these oxides, the q and PF values are minimum and maximum, respectively, for x = 0.01. However, the presence of spinel impurities even for x = 0.01 in Zn 1Àx Al x O or for x = 0.02 in CuCr 1Àx Mg x O 2 calls into question the role of the doping element in the physical properties. This should motivate a deeper insight into the physics of thermoelectric oxides.

show abstract

Section: P-type Oxides: Delafossitesmentioning

confidence: 99%

Thermoelectric Oxides: Effect of Doping in Delafossites and Zinc Oxide

Guilmeau

Maignan

Martin

2009

Journal of Elec Materi

View full text Add to dashboard Cite

show abstract

“…Otherwise, the optical transmittance of CuCr 1−x Mg x O 2 film was in the range of 30-40% in the visible region. Recently, CuCr 1−x Mg x O 2 bulks [18] and films have been studied extensively to obtain relatively high conductivity and optical transparency in the visible spectrum [19]. Ferromagnetic transitions were found in Mn-doped CuCrO 2 bulks, * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of CuCr1−xMgxO2 films prepared by pulsed laser deposition

Fang

Deng

et al. 2009

Journal of Alloys and Compounds

View full text Add to dashboard Cite

“…the Ca, Al doping in CuCrO 2 . [12,13] But the Mg substitution for Cr leads to the sharpen of the AFM transition and the large enhancement of magnetization around T N , which means that the magnetic order is enhanced by Mg doping. [9,12] This is thought to stem from the partially lifted residual magnetic frustration due to spin fluctuations, which are enhanced through the interaction between the hole introduced by Mg doping and the localized Cr spins.…”

mentioning

confidence: 99%

Spin dynamics in triangular-lattice antiferromagnets CuCr _{1−
x} Mg _x O ₂

Li¹,

Qu²,

Wei³

et al. 2011

EPL

View full text Add to dashboard Cite

Abstract. -The electron spin resonance (ESR) spectroscopy was employed to investigate the spin dynamics in triangular lattice antiferromagnets CuCr1−xMgxO2 with x = 0 and 0.02. All spectra can be well fitted by a single Lorentzian lineshape. The analysis of the g factor, the linewidth △H, and the ESR intensity I as a function of temperature suggests the development of significant antiferromagnetic (AFM) spin fluctuations at temperature well above TN in both samples. However, the evolution of the AFM spin fluctuations is different for each sample. For undoped sample the ESR intensity I is almost temperature independent between ∼ 100 K and 50 K and then drops rapidly below 50 K. But for x = 0.02, the I monotonously increases with cooling and reduces rapidly only below TN . These results indicate that the AFM spin fluctuations are extremely strong in the undoped sample and appear to be suppressed upon Mg doping.Introduction. -Triangular lattice antiferromagnets (TLAs) have attracted considerable interests because geometrical spin frustration inherent to these systems results in exceptionally rich physical properties ranging over spin liquid, [1, 2] quantum phase transition, [3] anomalous large thermoelectric response, [4] superconductivity, [5] and magnetoelectric properties. [6][7][8] A typical example of TLAs is CuCrO 2 ; it has a delafossite structure, which can be viewed as the alternate stacking of edge-shared CrO 6 octahedral layers and Cu layers along the [001] axis (see the inset to Fig. 1). Cr ions form an antiferromagnetic (AFM) triangular sublattice, and the compound enters a long range AFM ordered state below the Néel temperature T N ∼ 26 K.[9] Previous powder neutron diffraction study proposed that the ground state has an out-of-plane incommensurate spiral-spin structure with an in-plane wave vector q = (0.329, 0.329, 0) below T N .[10] In this spiral-spin ordered phase, the compound exhibits ferroelectricity driven by the magnetic order, [8] whose polarization P can be tuned by using both magnetic and electric fields. [11] In addition, for CuCrO 2 the temperature dependence of magnetization starts to devi-

show abstract

Magnetic and transport properties of delafossite oxides CuCr1-x(Mg,Ca)x

Cited by 30 publications

References 2 publications

Thermoelectric Oxides: Effect of Doping in Delafossites and Zinc Oxide

Thermoelectric Oxides: Effect of Doping in Delafossites and Zinc Oxide

Characteristics of CuCr1−xMgxO2 films prepared by pulsed laser deposition

Spin dynamics in triangular-lattice antiferromagnets CuCr _{1−
x} Mg _x O ₂

Contact Info

Product

Resources

About

Magnetic and transport properties of delafossite oxides CuCr1-x(Mg,Ca)x

Cited by 30 publications

References 2 publications

Thermoelectric Oxides: Effect of Doping in Delafossites and Zinc Oxide

Thermoelectric Oxides: Effect of Doping in Delafossites and Zinc Oxide

Characteristics of CuCr1−xMgxO2 films prepared by pulsed laser deposition

Spin dynamics in triangular-lattice antiferromagnets CuCr 1− x Mg x O 2

Contact Info

Product

Resources

About

Spin dynamics in triangular-lattice antiferromagnets CuCr _{1−
x} Mg _x O ₂