Synthesis, structure, magnetic and photoelectric properties of Ln₃M_0.5M′Se₇ (Ln = La, Ce, Sm; M = Fe, Mn; M′ = Si, Ge) and La₃MnGaSe₇

Abstract

Six new isostructural compounds, with the formulas of La3Fe0.5GeSe7, La3MnGaSe7, Ce3Fe0.5SiSe7, Ce3Mn0.5SiSe7, Sm3Fe0.5SiSe7 and Sm3Mn0.5GeSe7, have been successfully synthesized via molten salt method. Their structures are determined by single crystal X-ray diffraction and they crystallize in the Ce6Al3.33S14 structure type (space group: P63, Pearson symbol: hP24). Pure phases of the Ce3Fe0.5SiSe7, Ce3Mn0.5SiSe7, Sm3Fe0.5SiSe7 and Sm3Mn0.5GeSe7 compounds were obtained by solid state reaction and were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), ultraviolet-visible light (UV-Vis) spectroscope, and magnetization measurements. The Ce3Fe0.5SiSe7 and Ce3Mn0.5SiSe7 compounds show paramagnetic domination accompanied by antiferromagnetic contributions, while the Sm3Mn0.5GeSe7 and Sm3Fe0.5SiSe7 compounds show anti-ferromagnetic phase transitions with Néel temperatures of 13K and 24K, respectively. Optical measurements reveal that all of the four compounds can absorb most of visible light. These four compounds also show photo response properties with the photocurrent densities of 81, 1.3, 1.8 and 0.8 µA⋅cm -2 , respectively. 34 Hence, in this work, we report six new rare earth selenides, containing magnetic active d-block elements (Mn, Fe) of the Ln

Recent Developments on Molten Salt Synthesis of Inorganic Nanomaterials: A Review

“…A few more chalcogenides and related materials have also been successfully synthesized by the MSS strategy, such as Fe­(Se 0.5 Te 0.5 ) solid pellet, 1D zinc selenophosphates, sulfur-doped silicon, La 3 Fe 0.5 GeSe 7 , La 3 MnGaSe 7 , Ce 3 Fe 0.5 SiSe 7 , Ce 3 Mn 0.5 SiSe 7 , Sm 3 Fe 0.5 SiSe 7 , Sm 3 Mn 0.5 GeSe 7 , Cu 10 Cd 2 Sb 4 S 13 , etc. − The MSS has also been employed to prepare chalocogenide-related heterojunctions. For example, Zhong et al synthesized TiO 2 NP@MoS 2 nanosheet heterojunction using the MSS strategy (Figure d–f) .…”

Synthesis, Crystal Growth, Electronic Properties and Optical Properties of Y6IV2.5S14 (IV=Si, Ge)

“…For the chemical formula RE 6 B x C y Ch 14 , elements that can be found occupying the RE atomic position are presented in yellow, elements that can be found occupying the B atomic position are presented in orange, elements that can be found occupying the C atomic position are presented in blue, and elements that can be found occupying the Ch atomic position are presented in green. The broad structural flexibility of the RE 6 B x C y Ch 14 family results in properties such as variable bandgaps spanning 1.13 eV (Sm 3 Fe 0.5 SiSe 7 [3] ) to 3.01 eV (La 3 LiGeS 7 [1] ), and intriguing nonlinear optical properties, such as in La 3 GaGe 0.5 S 7 (4.8 × AgGaS 2 [2] ). As the first few reported compounds in the RE 6 B x C y Ch 14 family, Y 6 Si 2.5 S 14 and Y 6 Ge 2.5 S 14 were discovered in 1969.…”

BaGa2SnSe6: a new phase-matchable IR nonlinear optical material with strong second harmonic generation response

“…Desirable properties for an IR NLO material include (1) a large NLO coefficient to increase the energy conversion efficiency, (2) a sufficiently large birefringence (Dn) to satisfy the phase-matching requirement, (3) a wide IR transparency region, (4) a high laser-induced damage threshold and (5) good chemical and thermal stability. 15 During the last few decades, research was widely carried out on metal chalcogenides, [16][17][18][19][20][21][22][23] a rich source of IR nonlinear optical materials. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Compared with oxides, metal chalcogenides have a much broader IR transmission range and hence are more suitable for IR NLO applications.…”