High-Temperature Magnetic Ordering in a New Organic Magnet

Palácio, Fernando; Antorrena, Guillermo; Castro, Miguel; Burriel, R.; Rawson, Jeremy M.; Smith, J. Nicholas B.; Bricklebank, Neil; Novoa, Juan J.; Ritter, C.

doi:10.1103/physrevlett.79.2336

Cited by 144 publications

(81 citation statements)

References 16 publications

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“…The compounds 1 and 2 seem to have negligible intermolecular transfer interactions according to their insulating features and Curie-like magnetic behaviors. The radicals 4, 15, 84 and 16 [85][86][87] (Chart 4) have been developed based on the concept of the push-pull effect. Furthermore, the addition of the dithiadiazolyl ring is very efficient to stabilize radicals.…”

Section: Neutral -Radicalmentioning

confidence: 99%

“…88 They have a small t since there are no special intermolecular interactions between the radical moieties for appropriate packing. Hence, 16 is a typical Mott insulator and exhibits a weak ferromagnetism with canted antiferromagnetic interactions with T c ¼ 35:5 K. 85,86 The transition temperature is enhanced to 64.5 K by an application of pressure of 1.6 GPa. 87 Some selected organic conductors of neutral radicals and biradicals are presented in Table 5.…”

Section: Neutral -Radicalmentioning

confidence: 99%

See 1 more Smart Citation

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

Saito¹,

Yoshida²

2007

Bulletin of the Chemical Society of Japan

370

127

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Section: Neutral -Radicalmentioning

confidence: 99%

Section: Neutral -Radicalmentioning

confidence: 99%

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

Saito¹,

Yoshida²

2007

Bulletin of the Chemical Society of Japan

370

127

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“…20 Radicais orgânicos do tipo tiazil têm sido vistos como promissores na obtenção de magnetos orgânicos com transição de fase em temperaturas mais elevadas. 21,22 Medidas magnéticas revelaram que o derivado 3-cianobenzo-1,3,2-ditiazolilo apresenta uma transição de fase magneto-estrutural reversível a 250 K entre uma fase diamagnéti-ca, em baixa temperatura, e uma paramagnética em alta temperatura. A incorporação do grupo ciano na estrutura deste radical resultou em um empacotamento cristalino no qual as moléculas estão organizadas em lamelas, sendo as interações intermoleculares do tipo p ... p responsáveis por esta organização.…”

Section: Compostos Magnéticos Moleculares Puramente Orgânicosunclassified

Compostos magnéticos moleculares: o desenvolvimento de novos materiais magnéticos nanoestruturados

Guedes¹,

Allão²,

Mercante³

et al. 2010

Quím. Nova

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Recebido em 7/11/09; aceito em 21/4/10; publicado na web em 9/8/10 MOLECULAR MAGNETIC COMPOUNDS -THE DEVELOPMENT OF NEW NANOSTRUTURED MAGNETIC MATERIALS. The development of new magnetic materials has attracted attention of researchers of different areas. In the last decades, a distinguished class of materials emerged in magnetism, in which the magnetic moment is delocalized over molecules. By varying the synthetic conditions it is possible to obtain a large variety of structures and properties using the same starting molecules. These materials have a great scientific appeal due to the possibility of presenting not only magnetic, but also optical or electrical transport properties. In this review we will present an overview of some molecular magnetic compounds, in particular molecular nanomagnets.Keywords: molecular magnetic compounds; deposition on surfaces; magnetic materials. INTRODUÇÃOO magnetismo molecular é uma área de pesquisa interdisciplinar relativamente nova que pode ser considerada uma evolução da magnetoquímica.1 As possibilidades de atuação neste tema são amplas e pesquisadores de diversas especialidades estão trabalhando cada vez mais em conjunto. Esta interação envolve sínteses orgânica e inorgânica e o uso de técnicas de caracaterização magnética, difração de raios-x, eletroquímica e espectroscopias diversas, entre outras técnicas. Um dos objetivos é compreender a origem das propriedades magnéticas, sendo uma área que apresenta grandes desafios também para pesquisadores que fazem cálculos, envolvendo desde a simulação de dados experimentais até cálculos mais elaborados de modelagem molecular e energia dos sistemas possibilitando fazer correlações magneto-estruturais. 2Esta interdisciplinaridade tem possibilitado a descoberta e o entendimento de novos fenômenos como o tunelamento quântico da magnetização, coerência e emaranhamento quântico, que são fundamentais para aplicações na área de computação quântica. Além disso, outro grande atrativo é que estes materiais moleculares podem apresentar sinergia entre propriedades magnéticas, condutoras e ópticas, o que é interessante para aplicações tecnológicas. 4 Neste artigo de revisão são apresentadas algumas das diversas estratégias utilizadas na síntese de compostos magnéticos moleculares. Também será abordado o progresso na obtenção e deposição em superfícies de um dos sistemas mais interessantes da área, os chamados magnetos de uma molécula ou nanomagnetos moleculares. Esta é uma etapa de extrema importância que visa a formação de sistemas magnéticos nanoestruturados para aplicação em dispositivos. COMPOSTOS MAGNÉTICOS MOLECULARES PURAMENTE ORGÂNICOSMoléculas orgânicas paramagnéticas são conhecidas por apresentarem alta reatividade, além de não serem estáveis termicamente. No entanto, certas classes de radicais orgânicos apresentam estabilidade à temperatura ambiente e relativa facilidade sintética, o que vêm fascinando químicos e físicos pela variedade de propriedades magnéticas, ópticas e condutoras que podem exibir. 5O estudo das propriedades magn...

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“…The target compound is the organic weak-ferromagnets p-O 2 N-C 6 F 4 -CNSSN, which has the highest Tc (= 35.5 K at ambient pressure) among genuine organic molecule-based magnets. 16) Figure 4 shows the temperature dependence of the magnetization M (H = 1000 Oe) in the pressure region up to 1.64 GPa. Here, the pressure value is one estimated as P h .…”

Section: Miniature Diamond Anvil Cellmentioning

confidence: 99%

Magnetic Measurements on Molecule-Based Magnets under High Pressure

Mito

2007

J. Phys. Soc. Jpn.

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The effects of pressure on two prototypes of molecule-based magnets have been investigated through dc magnetic measurements in an attempt to realize these higher transition temperatures (T C 's). The target compounds are (1) a genuine organic radical weak-ferromagnet, p-NC-C 6 F 4 -CNSSN (T C = 35.5 K) with through-space intermolecular interaction and (2) a metal-complex ferrimagnet [Mn(en)] 3 [Cr(CN) 6 ] 2 •4H 2 O (T C = 69 K) with a cyanide bridge network between magnetic metal ions. In (1), T C is enhanced as dT C /dP = 22.0 K/GPa, and it exceeds 70 K at around 1.5 GPa. Exceeding a border of 70 K is worthy in the field of the genuine organic system. In (2), pressure dependences of T C and magnetic moment have been investigated over wider pressure region. The ideal material control for higher-T C was realized at around 5 GPa. Two types of pressure cells developed for these studies are also mentioned.KEYWORDS: molecule-based magnets, magnetic susceptibility, high pressure, pressure cell IntroductionIn recent days, much attention of material scientists has been devoted to a molecule-based magnetic system, called as molecule-based magnet, from the interest of the magneto-structural correlation and the viewpoints of new functionality due to nano-size effect, giant molecules and the topology.1, 2) The studies of the above-mentioned moleculebased magnets are divided into two, below.The first category is a genuine organic system without magnetic metal ions. There are furthermore two strategies on constructing the magneto-structural correlation; through-space interaction in an organic radical system and through-bond one in an organic polymer one. These compounds belonging to the first category are commonly soft, flexible and brittle. In this sense, the structural control via applying pressure presents us wealthy information about the interaction mechanism.3) In the case of organic radical system, intermolecular SOMO (single-occupied molecular orbital)-SOMO overlap favors the antiferromagnetic spin configuration, while the overlappings such as SOMO-HOMO (highest occupied MO) and SOMO-LUMO (lowest unoccupied MO) encourage the ferromagnetic correlation. Under a forced shrinkage by applying pressure, the former is relatively easy to be enlarged, whereas the latter often weakens. 4,5) Thus, pressurization can work as a negative factor on enhancing the ferromagnetic transition temperature T C . If we hope to construct a higher-T C magnet by using a technique of pressurization, it is reasonable to seek after higher-T C in a weak-ferromagnetic system with antiferromagnetic frame and the slight magnetic anisotropy.

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High-Temperature Magnetic Ordering in a New Organic Magnet

Cited by 144 publications

References 16 publications

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

Compostos magnéticos moleculares: o desenvolvimento de novos materiais magnéticos nanoestruturados

Magnetic Measurements on Molecule-Based Magnets under High Pressure

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