Thermal Expansion, Heat Capacity, and Thermal Conductivity of Nickel Ferrite (NiFe₂O₄)

Abstract

Nickel ferrite (NiFe 2 O 4 ) is major constituent of the oxide formed on the exterior of nuclear fuel cladding tubes during operation, which is comprised of corrosion products. Due to the impact of this oxide layer (typically referred to as CRUD) on the operation of commercial nuclear reactors, NiFe 2 O 4 has attracted interest. Although advances have been made in modeling CRUD nucleation and growth under a wide range of conditions, the thermophysical properties of NiFe 2 O 4 at high temperatures have only been approximated, thereby limiting the accuracy of such models. In this study, samples of NiFe 2 O 4 were synthesized in order to provide the thermal diffusivity, specific heat capacity, and thermal expansion data from room temperature to 1300K. These results were then used to determine thermal conductivity. Numerical fits are provided to facilitate ongoing modeling efforts. The Curie temperature determined through these measurements was in slight disagreement with literature values. Transmission electron microscopy investigation of multiple NiFe 2 O 4 samples revealed that minor nonstoichiometry was likely responsible for variations in the Curie temperature. However, these small changes in composition did not impact the thermal conductivity of NiFe 2 O 4 , and thus are not expected to play a large role * Corresponding Author

Thermal properties of Ti-doped Cu–Zn soft ferrites used as thermally actuated material for magnetizing superconductors

“…In the temperature range of 2 -300 K the coefficient changes monotonically from 0.2 Wm -1 K -1 at the lowest temperature to approximately 2.5 -3 Wm -1 K -1 at the highest investigated temperature. These high-temperature values are close to the majority of other ferrite materials [46]. Initially, up to ~ 30 K the thermal conductivity changes ~ T 1.6 .…”

“…Results are shown in figure 6. The thermal diffusivity over the whole investigated temperature range is a little higher for Mg0.15Cu0.15Zn0.7Ti0.04Fe1.96O4 than for Cu0.3Zn0.7Ti0.04Fe1.96O4 ferrite and both are comparable to the group of ceramics showing rather low thermal diffusivity coefficient [46].…”

Quantitative Disentanglement of the Spin Seebeck, Proximity-Induced, and Ferromagnetic-Induced Anomalous Nernst Effect in Normal-Metal–Ferromagnet Bilayers

“…Further details on the heat flux normalization can be found in the Supplemental Materials III [30] (including Refs. [35,36]). To estimate the ANE reduction due to the additional Pt layer we used the ratio of conductances G of the NiFe 2 O x and the Pt in a parallel arrangement [14] …”

Structural and magnetic properties of CoFe2O4/NiFe2O4 core/shell nanocomposite prepared by the hydrothermal method

“…These properties, along with their greatest physical and chemical stability, make CoFe 2 O 4 nanoparticles suitable for high density information recording, ferrofluid technology, storage systems, clinical and biological applications [1], [4][5][6][7][8]. On the other hand,Nickel ferrite (NiFe 2 O 4 ) is one of the versatile and technologically important soft ferrite (low anisotropy field) materials with spinel structure because of its typical ferromagnetic properties, low electrical conductivity and thus lower eddy current losses, high electrochemical stability, catalytic behavior and abundance in nature [9][10][11][12].…”