Thermoelectric and Magnetic Properties of a Narrow-Gap Semiconductor FeGa<sub>3</sub>

Hadano, Yuta; Narazu, Shouta; Ávila, M. A.; Onimaru, Takahiro; Takabatake, Toshiro

doi:10.1143/jpsj.78.013702

Cited by 78 publications

(136 citation statements)

References 24 publications

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“…While at x ≥ 0.075 the solid solution exhibits metallic behavior, a significant increase in the resistivity upon cooling below 150 K is observed for x = 0.01 and 0.025. It is known from the literature 16 that the resistivity of pure FeGa 3 has different regimes in various temperature ranges. In comparison with FeGa 3 , the behavior of the solid solution for x = 0.01 and 0.025 can be described as follows: for 150 < T < 300 K the saturation of thermally activated impurity donors is observed, while for 4 < T < 150 K the impurity donors are frozen out.…”

Section: A Electrical Resistivitymentioning

confidence: 99%

Interplay between localized and itinerant magnetism in Co-substituted FeGa3

et al. 2014

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The evolution of the electronic structure and magnetic properties with Co substitution for Fe in the solid solution Fe1−xCoxGa3 was studied by means of electrical resistivity, magnetization, ab initio band structure calculations, and nuclear spin-lattice relaxation 1/T1 of the 69,71 Ga nuclei. Temperature dependencies of the electrical resistivity reveal that the evolution from the semiconducting to the metallic state in the Fe1−xCoxGa3 system occurs at 0.025 < x < 0.075. The 69,71 (1/T1) was studied as a function of temperature in a wide temperature range of 2−300 K for the concentrations x = 0.0, 0.5, and 1.0. In the parent semiconducting compound FeGa3, the temperature dependence of the 69 (1/T1) exhibits a huge maximum at about T ∼ 6 K indicating the existence of in-gap states. The opposite binary compound, CoGa3, demonstrates a metallic Korringa behavior with 1/T1 ∝ T . In Fe0.5Co0.5Ga3, the relaxation is strongly enhanced due to spin fluctuations and follows 1/T1 ∝ T 1/2 , which is a unique feature of weakly and nearly antiferromagnetic metals. This itinerant antiferromagnetic behavior contrasts with both magnetization measurements, showing localized magnetism with a relatively low effective moment of about 0.7 µB/f.u., and ab initio band structure calculations, where a ferromagnetic state with an ordered moment of 0.5 µB/f.u. is predicted. The results are discussed in terms of the interplay between the localized and itinerant magnetism including in-gap states and spin fluctuations.

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Section: A Electrical Resistivitymentioning

confidence: 99%

Interplay between localized and itinerant magnetism in Co-substituted FeGa3

et al. 2014

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“…These low bandgap semiconductors with large density of states near the Fermi level show a promise for application as thermoelectric material. FeGa 3 shows a large negative Seebeck coefficient with the value of 563 µV/K for polycrystalline sample 9 and 350 µV/K for single crystal 10 which has attracted the deep interest for an understanding of the electronic structure of this material.…”

Section: Introductionmentioning

confidence: 99%

“…Temperature dependent resistivity measurements have led to a gap of ≈ 0.20 eV 11 , 0.26 eV 5 and 0.50 eV 9,10 . Temperature dependent magnetic succeptibility measurement at high temperature shows an activated type behavior, with the bandgap values between 0.29-0.45 eV 12 .…”

Section: Introductionmentioning

confidence: 99%

Structural and electronic properties of Fe(Al_xGa_1–_x)₃ system

Mondal

Kamal

Banik

et al. 2016

Journal of Applied Physics

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FeGa3 is a well known d-p hybridization induced intermetallic bandgap semiconductor. In this work, we present the experimental and theoretical results on the effect of Al substitution in FeGa3, obtained by x-ray diffraction (XRD), temperature dependent resistance measurement, room temperature Mossbauer measurements and density functional theory based electronic structure calculations. It is observed that upto x = 0.178 in Fe(AlxGa1−x)3, which is the maximum range studied in this work, Al substitution reduces the lattice parameters a and c preserving the parent tetragonal P42/mnm crystal structure of FeGa3. The bandgap of Fe(AlxGa1−x)3 for x = 0.178 is reduced by ≈ 24% as compared to FeGa3. Rietveld refinement of the XRD data shows that the Al atoms replace Ga atoms located at the 8j sites in FeGa3. A comparison of the trends of the lattice parameters and energy bandgap observed in the calculations and the experiments also confirms that Al primarily replaces the Ga atoms in the 8j site.

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“…Представителя-ми указанной группы материалов являются бинарные соединения FeGa 3 и RuGa 3 , обладающие тетрагональ-ной кристаллической структурой типа FeGa 3 (простран-ственная группа симметрии P4 2 /mnm). Температурные зависимости электронных и магнитных свойств этих соединений носят ярко выраженный полупроводниковый характер [1][2][3][4][5][6][7], а рассчитанные плотности электронных состояний показывают наличие энергетических щелей размером в десятые доли электронвольта [1,5,[8][9][10][11]. Формирование таких щелей на уровне Ферми связыва-ется с особенностями гибридизации протяженных s−p зон Ga и узких d зон Fe (Ru) в энергетических спектрах данных материалов, а разброс в оценках их ширины находится в пределах 0.3−0.6 eV.…”

Section: Introductionunclassified

“…Результаты расчетов электронной структуры использовали при интерпрета-ции магнитных и транспортных свойств FeGa 3 и RuGa 3 . В частности, аномалия зонного спектра, связанная с энергетической щелью на E F , определяет поведение температурных зависимостей удельной теплоемкости, электросопротивления, эффекта Холла, коэффициента Зеебека [4][5][6][12][13][14][15][16]. Подобная щель (≤ 0.8 eV) была за-фиксирована в фотоэмиссионных спектрах FeGa 3 [17,18].…”

Section: Introductionunclassified

Исследование структуры электронных состояний соединений FeGa-=SUB=-3-=/SUB=- и RuGa-=SUB=-3-=/SUB=- методом оптической спектроскопии

Князев¹,

Кузьмин²

2017

Физика Твердого Тела

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Проведены исследования оптических свойств интерметаллических соединений FeGa3 и RuGa3 в интервале длин волн 0.22-14 mum. Спектры межзонного поглощения света интерпретируются на основе сравнительного анализа рассчитанных и экспериментальных дисперсионных зависимостей оптической проводимости. Экспериментальные данные подтверждают существование в плотностях состояний данных материалов энергетических щелей на уровне Ферми шириной ~0.6 eV, что ранее предсказывалось в зонных расчетах. Работа выполнена в рамках государственного задания ФАНО России (тема "Электрон", N 01201463326) при частичной поддержке РФФИ (проект N 17-52-45056). DOI: 10.21883/FTT.2017.11.45065.138

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Thermoelectric and Magnetic Properties of a Narrow-Gap Semiconductor FeGa₃

Cited by 78 publications

References 24 publications

Interplay between localized and itinerant magnetism in Co-substituted FeGa3

Interplay between localized and itinerant magnetism in Co-substituted FeGa3

Structural and electronic properties of Fe(Al_xGa_1–_x)₃ system

Исследование структуры электронных состояний соединений FeGa-=SUB=-3-=/SUB=- и RuGa-=SUB=-3-=/SUB=- методом оптической спектроскопии

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Thermoelectric and Magnetic Properties of a Narrow-Gap Semiconductor FeGa3

Cited by 78 publications

References 24 publications

Interplay between localized and itinerant magnetism in Co-substituted FeGa3

Interplay between localized and itinerant magnetism in Co-substituted FeGa3

Structural and electronic properties of Fe(AlxGa1–x)3 system

Исследование структуры электронных состояний соединений FeGa-=SUB=-3-=/SUB=- и RuGa-=SUB=-3-=/SUB=- методом оптической спектроскопии

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Thermoelectric and Magnetic Properties of a Narrow-Gap Semiconductor FeGa₃

Structural and electronic properties of Fe(Al_xGa_1–_x)₃ system