Layered alkali rhodium oxides AxRhO2: Topotactic solvation, exchange, and redox reactions

Mendiboure, A.; Eickenbusch, H.; Schöllhorn, R.; Rao, G. V. Subba

doi:10.1016/0022-4596(87)90137-x

Cited by 31 publications

(30 citation statements)

References 14 publications

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“…However, our optimized value of c is similar to other isostructural layered oxides such as Sr x RhO 2 [27,28], Na x CoO 2 [7], Li x NbO 2 [29], and La x CoO 2 [30]. In addition, LiRhO 2 , NaRhO 2 , and KRhO 2 layered oxides can form a hydrate (water intercalated) phase [19] with an increased c length [31]. Takada et al [4] showed that Na x CoO 2 can be readily hydrated to form Na x CoO 2 yH 2 O, maintaining the CoO 2 layers, but with a considerably expanded c axis, to accomodate the intercalated water.…”

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confidence: 72%

Colossal Thermoelectric Power Factor in K_7/8RhO₂

Saeed

Singh

Schwingenschlögl

2012

Adv Funct Materials

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We discuss the thermoelectric and optical properties of layered KxRhO2 (x = 1/2 and 7/8) in terms of the electronic structure determined by first principles calculations as well as Boltzmann transport theory. Our optimized lattice constants differ significantly from the experiment, but result in optical and transport properties close to the experiment. The main contribution to the optical spectra are due to intra and inter-band transitions between the Rh 4d and O 2p states. We find a similar power factor for pristine KxRhO2 at low and high cation concentartions. Our transport results of hydrated KxRhO2 at room temperature show highest value of the power factor among the hole-type materials. Specially at 100 K, we obtain a value of 3×10 −3 K −1 for K 7/8 RhO2, which is larger than that of Na0.88CoO2 [M. Lee et al., Nat. Mater. 5, 537 (2006)]. In general, the electronic and optical properties of KxRhO2 are similar to NaxCoO2 with enhanced transport properties in the hydrated phase.

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confidence: 72%

Colossal Thermoelectric Power Factor in K_7/8RhO₂

Saeed

Singh

Schwingenschlögl

2012

Adv Funct Materials

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“…Recently, we successfully prepared single-crystalline samples of K 0.49 RhO 2 [19]. However, there are few reports on A x RhO 2 (A : alkali metals) and its hydrated form [20,21,22,23], and no report on their thermoelectric properties. Figure 1 shows the crystal structure of K 0.49 RhO 2 and a photographic image of a sample [24].…”

Section: Introductionmentioning

confidence: 99%

Transport properties of the layered Rh oxide K_0.49RhO₂

Shibasaki

Nakano

Terasaki

et al. 2010

J. Phys.: Condens. Matter

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We report measurements and analyses of resistivity, thermopower and Hall coefficient of singlecrystalline samples of the layered Rh oxide K 0.49 RhO 2 . The resistivity is proportional to the square of temperature up to 300 K, and the thermopower is proportional to temperature up to 140 K.The Hall coefficient increases linearly with temperature above 100 K, which is ascribed to the triangular network of Rh in this compound. The different transport properties between Na x CoO 2 and K 0.49 RhO 2 are discussed on the basis of the different band width between Co and Rh evaluated from the magnetotransport.

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“…5a), are typical of layered material with a turbostratic disorder of the layers stacking: indeed, one observes sharp and symmetric reflections for the basal (00l) planes and broad and asymmetric reflections for the non-basal planes [10]. The interlamellar distance (12.86 Å) is slightly higher than that previously observed by Mendiboure et al(12.03Å) [7]. The turbostratic feature is confirmed by TEM: LDH-Ni-Fe-Ac powder appears as aggregates of thin crumpled sheets with any definite shape (Fig.…”

Section: Chemical and Physical Characteristics Of Ldh-ni-fe Powder Anmentioning

confidence: 54%

Powder and film of nickel and iron-layered double hydroxide: Elaboration in polyol medium and characterization

Taibi

Ammar

Schoenstein

et al. 2008

Journal of Physics and Chemistry of Solids

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Two main reactions occur in polyol media: reduction and hydrolysis. In the case of systems with two easily reducible elements Ni and Fe for instance, previous works have shown that bimetallic particles or the oxide spinel particles can be obtained. This paper shows that polyols can also be used to elaborate Layered Double Hydroxides LDH-Ni-Fe. In this case, the hydrolysis ratio must be adjusted to avoid both reduction and oxolation reactions in favor of hydroxylation. The compound can be obtained either in powder or gel forms. The gel enables elaboration of film by spin-coating process. The compound is poor-crystallised and exhibits a turbostractic character. Its interlamellar distance (12.89Å) is slightly higher than that of similar compound elaborated in aqueous solution via titration method (12.02Å).57 FeMössbauer spectrometry allows to conclude to the presence of HS Fe 3+ cations which occupy two different octahedral sites. XRD and Mössbauer studies reveal interesting preferential orientation features of the film with an anisotropy of the crystalline grains having their c axis perpendicular to the film.

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Layered alkali rhodium oxides AxRhO2: Topotactic solvation, exchange, and redox reactions

Cited by 31 publications

References 14 publications

Colossal Thermoelectric Power Factor in K_7/8RhO₂

Colossal Thermoelectric Power Factor in K_7/8RhO₂

Transport properties of the layered Rh oxide K_0.49RhO₂

Powder and film of nickel and iron-layered double hydroxide: Elaboration in polyol medium and characterization

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Layered alkali rhodium oxides AxRhO2: Topotactic solvation, exchange, and redox reactions

Cited by 31 publications

References 14 publications

Colossal Thermoelectric Power Factor in K7/8RhO2

Colossal Thermoelectric Power Factor in K7/8RhO2

Transport properties of the layered Rh oxide K0.49RhO2

Powder and film of nickel and iron-layered double hydroxide: Elaboration in polyol medium and characterization

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Colossal Thermoelectric Power Factor in K_7/8RhO₂

Colossal Thermoelectric Power Factor in K_7/8RhO₂

Transport properties of the layered Rh oxide K_0.49RhO₂