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Due to remarkable dielectric features, such as a large dielectric constant, strong electrical conductivity, high capacitance, and low dielectric loss, hybrid materials have lately seen a huge number of applications in the field of optoelectronics. These are critical characteristics that qualify the performance of optoelectronic devices, particularly field-effect transistor components (FETs). Here, the hybrid compound 2-amino-5-picoline tetrachloroferrate(iii) (2A5PFeCl 4 ) was synthesised by using the slow evaporation solution growth method at room temperature. Structural, optical, and dielectric properties have been investigated. The 2A5PFeCl 4 compound crystallises in the monoclinic system ( P 2 1 / c space group). Its structure can be described as a successive layering of inorganic and organic parts. [FeCl 4 ] - tetrahedral anions and 2-amino-5-picolinium cations are connected by N-H⋯Cl and C-H⋯Cl hydrogen bonds. The optical absorption measurement confirms the semiconductor nature with a band gap of around 2.47 eV. Additionally, the structural and electronic properties of the title compound have been investigated theoretically through DFT calculations. At low frequencies, this material has significant dielectric constants ( ε ∼10 6 ). Furthermore, the high electrical conductivity, low dielectric loss at high frequencies, and high capacitance show that this new material has great dielectric potential in FET technologies. Due to their high permittivity, these compounds can be employed as gate dielectrics., Competing Interests: The authors declare no competing interests., (This journal is © The Royal Society of Chemistry.)

Ferrite compounds have recently attracted significant interest because of their multifunctional properties. This work investigates the optical, magnetic, and dielectric properties of a LiMn 0.5 Fe 2 O 4 ferrite prepared by a solid-state reaction. Raman spectroscopy analysis substantiated the presence of the 5 active modes representing the vibration of the oxygen anion at both tetrahedral and octahedral sites. The direct optical band gap was estimated to be 3.51 eV, which indicates the semiconductor behavior of the compound. A theoretical modulation of the hysteresis loop was done to confirm the dominance of the ferromagnetic contribution over the antiferromagnetic one. Furthermore, the dielectric permittivity result indicated a colossal value of the order of 10 3 . The dielectric losses are characterized by the Giuntini law to extract the relaxation process, which is hidden by the DC-conductivity process. Our results indicate the potential of LiMn 0.5 Fe 2 O 4 for applications in multifunctional devices., Competing Interests: The authors declare that there are no competing interests regarding the publication of this paper., (This journal is © The Royal Society of Chemistry.)

The development of multifunctional materials is an exceptional research area, which is aimed at enhancing the versatility of materials in various applications. In this context, the exceptional properties of ferrite materials have attracted the attention of researchers. For this reason, we synthesized LiMn 0.5 Fe 2 O 4 sintered at a temperature of 1100 °C. The X-ray powder diffraction analysis reveals the presence of one cubic phase with the Fd 3̄ m space group and confirms the spinel structure formation. Moreover, the elemental analysis by EDX reveals the homogeneous distribution of iron and manganese cations. Scanning electron microscopy shows that the grain size is of the order of 2.48 μm. Impedance spectroscopy was performed in the temperature and frequency ranges from 200 K to 380 K and 40 Hz to 10 6 Hz, respectively. The Nyquist plots revealed the presence of grains and grain boundary contributions. The semiconductor nature, obtained by the conductivity study, indicates that LiMn 0.5 Fe 2 O 4 is promising in optoelectronic applications. Dc conductivity is found to be thermally activated with an activation energy of 370 meV, 255 meV, and 199 meV for 200-270 K, 280-330 K, and 340-380 K regions, respectively. From the Jonscher power law, the correlated barrier hopping model (CBH) and non-overlapping small polaron tunneling (NSPT) prevailed in the conduction process. Besides, the temperature coefficient of resistivity (TCR) affirmed that LiMn 0.5 Fe 2 O 4 is a good candidate for detecting infrared radiations and infrared bolometric applications., Competing Interests: Authors declare that they have no conflict of interest or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

The alkylammonium halogenoferrate families are subjected to diverse studies according to their wide field application. However, these compounds show various transitions depending on the preparation process. In this paper, the [(C 2 H 5 ) 4 N]FeCl 4 compound was successfully synthesized using a slow evaporation solution growth method at room temperature. An optical absorption measurement confirms the semiconductor nature with a band gap around 2.95 eV. The X-ray powder diffraction (XRPD) data confirmed the formation of a single-phase with hexagonal-type structure. The differential scanning calorimetry (DSC) indicated that the [(C 2 H 5 ) 4 N]FeCl 4 compound undergoes eight reversible phase transitions between 193 and 443 K. At high temperature ( T > 423 K) the plastic nature of the crystals was confirmed. Temperature-controlled X-ray diffraction reveals that the thermal expansion of the crystal structure is non homothetic in the ( a , b ) plane and along the c axis. The temperature dependence of the Raman spectra up to 443 K revealed specific reorientations and molecular displacements of the organic and inorganic components associated with the phase transitions. We aim to thermally stabilize the [(C 2 H 5 ) 4 N]FeCl 4 compound which has a band gap suitable for photocatalytic processes., Competing Interests: All authors have no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

The compound, tetraethylammonium tetrachloroferrate [(C 2 H 5 ) 4 N]FeCl 4 , was prepared by slow evaporation at room temperature. It was characterized by X-ray powder diffraction, thermal analysis, and impedance and vibrational spectroscopy. X-ray diffraction data confirmed formation of a single phase material which crystallized at room temperature in the hexagonal system ( P 6 3 space group). DSC showed the existence of two phase transitions at 413 K and 430 K. Electrical conductivity was measured in the temperature and frequency ranges of 390 K to 440 K and 40 Hz to 110 MHz, respectively. Nyquist plots revealed the existence of grains and grain boundaries that were fitted to an equivalent circuit. AC conductivity plots were analyzed by Jonscher's power law. Variations in the " mc space group). DSC showed the existence of two phase transitions at 413 K and 430 K. Electrical conductivity was measured in the temperature and frequency ranges of 390 K to 440 K and 40 Hz to 110 MHz, respectively. Nyquist plots revealed the existence of grains and grain boundaries that were fitted to an equivalent circuit. AC conductivity plots were analyzed by Jonscher's power law. Variations in the " s " values indicated that CBH models describe the conduction mechanism in regions I and II. Temperature dependence of Raman spectra showed that the most important changes were observed in the cationic parts ([(C 2 H 5 ) 4 N] + ). The activation energy value obtained from the line width decreased which indicated an order-disorder model., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)