Heat dissipating multi-component inorganic mixture of iron with high-temperature dielectric behavior

Abstract

Synthesis and characterization of two multicomponent mixtures, 0.8 Fe₃(PO₄)₂ . 4H₂O . 0.8 FePO₄ . 2H₂O . 0.5 NH₄H₂PO₄ . 0.2(NH₄)₂SO₄ (FPN2A) and 0.8 Fe₃(PO₄)₂ .8H₂O. 0.8FePO₄. 0.5NH₄H₂PO₄ . 0.2(NH₄)₂SO₄ (FPN2B) are reported. FPN2A and FPN2B mixtures have average crystallite sizes of 66.1 nm and 79.5 nm, respectively. The respective optical bandgap of FPN2A and FPN2B are 6.02 eV and 5.96 eV with a refractive index of 1.99. Thermal analysis revealed heat-dissipating behaviour of the mixtures with specific heat capacity, C_P (at 307 K) of 0.71 Jg^-1K^-1 and 0.66 Jg^-1K^-1 for FPN2A and FPN2B, respectively. Further, temperature-frequency dependant dielectric properties of the FPN2C (obtained by sintering FPN2B at 423 K) have been investigated. The sintered mixture, FPN2C orchestrated variation in permittivity,  (∼ 17 – 42) and dielectric loss,  (∼ 0.04-0.08) in the frequency range of 1.0×10³ Hz to 4.0×10⁶ Hz up to 483 K. AC conductivity of FPN2C was found to be ∼ 8.96 ´ 10^-8 sm^-1 up to 483 K. TG-DSC analysis revealed the thermal stability of the FPN2C over a wide range of temperature (297 K to 1267 K) and heat-dissipating behaviour with a C_P of 0.62 Jg^-1K^-1.