Structural, magnetic, and electrical characterization of new polycrystalline phases of nickel- and platinum-doped [(DT-TTF) n][Au(mnt)2] (n = 1, 2)

Xavi Ribas; Angelo Sironi; Norberto Masciocchi; Elsa B. Lopes; Manuel Almeida; Jaume Veciana; Concepció Rovira

doi:10.1021/ic048484d

Structural, magnetic, and electrical characterization of new polycrystalline phases of nickel- and platinum-doped [(DT-TTF) _n][Au(mnt)₂] (n = 1, 2)

Xavi Ribas
, Angelo Sironi
, Norberto Masciocchi
, Elsa B. Lopes
, Manuel Almeida
, Jaume Veciana
, Concepció Rovira

CSIC - Institute of Materials Science of Barcelona
University of Milan
University of Insubria
Instituto Tecnológico e Nuclear

Research output: Contribution to journal › Scientific article › peer-review

15 Citations (Scopus)

Abstract

Doping of spin-ladder systems by isostructural paramagnetic complexes was attempted. Despite the close isostructural nature of the pure (DT-TTF) ₂[M(mnt)₂] (M = Au, Ni, Pt) end-members, which present a ladder structure, doping of the spin-ladder (DT-TTF)₂[Au(mnt) ₂] with either 5% or 25% [M(mnt)₂]^- (M = Ni, Pt) generates two (metrically) new phases. Their markedly different crystal structures have been determined using laboratory X-ray powder diffraction data. (DT-TTF)₂[Au_0.75Ni_0.25(mnt)₂] consists of a mixed-valence compound (of triclinic symmetry), which was only detected, pure or in a mixture of phases, when [Ni(mnt)₂]^- was used as a dopant. Differently, the stoichiometric 1:1 [DT-TTF][Au _0.75Pt_0.25(mnt)₂] monoclinic phase was found when [Pt(mnt)₂]^- (in 5% and 25%) was employed as the doping agent. Remarkably, only in the 5% Pt doping experiment, the major component of the mixture was the ladder structure compound (DT-TTF) ₂[Au(mnt)₂] doped with minor amounts of Pt. This 5% Pt-doped specimen shows an EPR signal (g = 2.0115, ΔH_pp = 114 G at 300 K) wider than the pure compound (DT-TTF)₂[Au(mnt) ₂], denoting exchange between the donor spins and Pt(mnt) ₂^- centers. The electrical transport properties of the 5% Pt-doped composition at high temperatures are comparable to those of (DT-TTF)₂[Au(mnt)₂] with room-temperature conductivity σ_300K = 13 S/cm and thermopower S_300K = 46 μV/K, with a sharp transition at 223 K similar to that previously observed in the Cu analogue at 235 K.

Original language	English
Pages (from-to)	2358-2366
Number of pages	9
Journal	Inorganic Chemistry
Volume	44
Issue number	7
DOIs	https://doi.org/10.1021/ic048484d
Publication status	Published - 7 Apr 2005
Externally published	Yes

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10.1021/ic048484d

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@article{f5abd00b80fb4123bbd980ae7986ae3f,

title = "Structural, magnetic, and electrical characterization of new polycrystalline phases of nickel- and platinum-doped [(DT-TTF) n][Au(mnt)2] (n = 1, 2)",

abstract = "Doping of spin-ladder systems by isostructural paramagnetic complexes was attempted. Despite the close isostructural nature of the pure (DT-TTF) 2[M(mnt)2] (M = Au, Ni, Pt) end-members, which present a ladder structure, doping of the spin-ladder (DT-TTF)2[Au(mnt) 2] with either 5\% or 25\% [M(mnt)2]- (M = Ni, Pt) generates two (metrically) new phases. Their markedly different crystal structures have been determined using laboratory X-ray powder diffraction data. (DT-TTF)2[Au0.75Ni0.25(mnt)2] consists of a mixed-valence compound (of triclinic symmetry), which was only detected, pure or in a mixture of phases, when [Ni(mnt)2]- was used as a dopant. Differently, the stoichiometric 1:1 [DT-TTF][Au 0.75Pt0.25(mnt)2] monoclinic phase was found when [Pt(mnt)2]- (in 5\% and 25\%) was employed as the doping agent. Remarkably, only in the 5\% Pt doping experiment, the major component of the mixture was the ladder structure compound (DT-TTF) 2[Au(mnt)2] doped with minor amounts of Pt. This 5\% Pt-doped specimen shows an EPR signal (g = 2.0115, ΔHpp = 114 G at 300 K) wider than the pure compound (DT-TTF)2[Au(mnt) 2], denoting exchange between the donor spins and Pt(mnt) 2- centers. The electrical transport properties of the 5\% Pt-doped composition at high temperatures are comparable to those of (DT-TTF)2[Au(mnt)2] with room-temperature conductivity σ300K = 13 S/cm and thermopower S300K = 46 μV/K, with a sharp transition at 223 K similar to that previously observed in the Cu analogue at 235 K.",

author = "Xavi Ribas and Angelo Sironi and Norberto Masciocchi and Lopes, \{Elsa B.\} and Manuel Almeida and Jaume Veciana and Concepci{\'o} Rovira",

year = "2005",

month = apr,

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doi = "10.1021/ic048484d",

language = "English",

volume = "44",

pages = "2358--2366",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

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T1 - Structural, magnetic, and electrical characterization of new polycrystalline phases of nickel- and platinum-doped [(DT-TTF) n][Au(mnt)2] (n = 1, 2)

AU - Ribas, Xavi

AU - Sironi, Angelo

AU - Masciocchi, Norberto

AU - Lopes, Elsa B.

AU - Almeida, Manuel

AU - Veciana, Jaume

AU - Rovira, Concepció

PY - 2005/4/7

Y1 - 2005/4/7

N2 - Doping of spin-ladder systems by isostructural paramagnetic complexes was attempted. Despite the close isostructural nature of the pure (DT-TTF) 2[M(mnt)2] (M = Au, Ni, Pt) end-members, which present a ladder structure, doping of the spin-ladder (DT-TTF)2[Au(mnt) 2] with either 5% or 25% [M(mnt)2]- (M = Ni, Pt) generates two (metrically) new phases. Their markedly different crystal structures have been determined using laboratory X-ray powder diffraction data. (DT-TTF)2[Au0.75Ni0.25(mnt)2] consists of a mixed-valence compound (of triclinic symmetry), which was only detected, pure or in a mixture of phases, when [Ni(mnt)2]- was used as a dopant. Differently, the stoichiometric 1:1 [DT-TTF][Au 0.75Pt0.25(mnt)2] monoclinic phase was found when [Pt(mnt)2]- (in 5% and 25%) was employed as the doping agent. Remarkably, only in the 5% Pt doping experiment, the major component of the mixture was the ladder structure compound (DT-TTF) 2[Au(mnt)2] doped with minor amounts of Pt. This 5% Pt-doped specimen shows an EPR signal (g = 2.0115, ΔHpp = 114 G at 300 K) wider than the pure compound (DT-TTF)2[Au(mnt) 2], denoting exchange between the donor spins and Pt(mnt) 2- centers. The electrical transport properties of the 5% Pt-doped composition at high temperatures are comparable to those of (DT-TTF)2[Au(mnt)2] with room-temperature conductivity σ300K = 13 S/cm and thermopower S300K = 46 μV/K, with a sharp transition at 223 K similar to that previously observed in the Cu analogue at 235 K.

AB - Doping of spin-ladder systems by isostructural paramagnetic complexes was attempted. Despite the close isostructural nature of the pure (DT-TTF) 2[M(mnt)2] (M = Au, Ni, Pt) end-members, which present a ladder structure, doping of the spin-ladder (DT-TTF)2[Au(mnt) 2] with either 5% or 25% [M(mnt)2]- (M = Ni, Pt) generates two (metrically) new phases. Their markedly different crystal structures have been determined using laboratory X-ray powder diffraction data. (DT-TTF)2[Au0.75Ni0.25(mnt)2] consists of a mixed-valence compound (of triclinic symmetry), which was only detected, pure or in a mixture of phases, when [Ni(mnt)2]- was used as a dopant. Differently, the stoichiometric 1:1 [DT-TTF][Au 0.75Pt0.25(mnt)2] monoclinic phase was found when [Pt(mnt)2]- (in 5% and 25%) was employed as the doping agent. Remarkably, only in the 5% Pt doping experiment, the major component of the mixture was the ladder structure compound (DT-TTF) 2[Au(mnt)2] doped with minor amounts of Pt. This 5% Pt-doped specimen shows an EPR signal (g = 2.0115, ΔHpp = 114 G at 300 K) wider than the pure compound (DT-TTF)2[Au(mnt) 2], denoting exchange between the donor spins and Pt(mnt) 2- centers. The electrical transport properties of the 5% Pt-doped composition at high temperatures are comparable to those of (DT-TTF)2[Au(mnt)2] with room-temperature conductivity σ300K = 13 S/cm and thermopower S300K = 46 μV/K, with a sharp transition at 223 K similar to that previously observed in the Cu analogue at 235 K.

UR - https://www.scopus.com/pages/publications/16244399501

U2 - 10.1021/ic048484d

DO - 10.1021/ic048484d

M3 - Scientific article

AN - SCOPUS:16244399501

SN - 0020-1669

VL - 44

SP - 2358

EP - 2366

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 7

ER -

Structural, magnetic, and electrical characterization of new polycrystalline phases of nickel- and platinum-doped [(DT-TTF) _n][Au(mnt)₂] (n = 1, 2)

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