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Zirconia (ZrO 2 )-based ceramics have dominated the engineering ceramics market for ages due to its diverse properties, for example, high strength, 1 notable hardness and toughness, 1,2 promising wear resistance, 3 bio-inertness, 4 high ionic conductivity, 5 modest coefficient of thermal expansion, 6 and elastic modulus similar to steel 7 (zirconia is also known as "ceramic steel" 7,8 ). High ionic conductivity in intermediate temperature makes the doped zirconia ceramics relevant for solid oxide fuel cell applications (as an electrolyte). 9,10 For biomedical applications, viz., in dentistry (for crown and bridge) 11 and prosthetic industry (as the ball heads for hip replacements), 12 ZrO 2 -based ceramics find its relevance due to its nontoxicity and mechanical integrity. For structural applications, zirconia-based ceramics are mostly used as cutting tools. 13 The other applications of zirconia involve fields like gas sensors, 14,15 refractories, 16 structural opacifiers, 17 and thermal barrier coating (TBC) 18 etc.Pure zirconia 5 has three crystalline polymorphic forms, namely monoclinic, tetragonal, and cubic. Among these polymorphs, monoclinic phase is stable at room temperature. At high temperature (>1170°C), there is a prominent volume expansion (~4%) associated with the tetragonal to monoclinic phase transformation (in zirconia bodies) during cooling. 7 This gives birth to microcracks and failure in the sintered zirconia ceramics and also makes pure, undoped zirconia (in monoclinic form) an unsuitable candidate for engineering applications. To overcome these undesired properties, generally, some amount of metal oxide stabilizers like yttria (Y 2 O 3 ), 11 calcia (CaO), 19 magnesia (MgO), 20 ceria (CeO 2 ) 21 etc. with different crystal structures (along with comparatively high solubility) in zirconia are doped. Doping stabilizes the high-temperature polymorphs, that is, tetragonal and cubic phases at ambient conditions. Doping of cations inside zirconia matrix results in decrease in particle/crystallite size, which ultimately stabilizes tetragonal structure of zirconia nanoparticles/ceramics. [22][23][24] Partially stabilized zirconia

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Various magnetic materials (for example, ferro, ferri, antiferromagnetic) are characterized by their respective transition temperatures (for example, Curie and Néel transitions). Knowledge of these transition temperatures is vital from an application standpoint. Accurate measurements by suitable characterization techniques are needed for identifying these transitions. Several techniques have been used to identify Curie and Néel transition temperatures, with thermal methods being one of the preferred choice. These thermal methods include differential scanning calorimetry (DSC), differential thermal analysis, and thermogravimetric analysis. Although thermal analysis tools have been popularly used for examining magnetic phase transitions, still much confusion exists on their efficacy and might. This review article highlights the strength and limitations of measuring Curie and Néel transitions by thermal techniques; measurements by DSC were the most common choice in previous works. Considering the intrinsic/fundamental nature of these Curie/Néel transitions, such confusion on their measurements (by thermal techniques) and their subsequent analysis (for the order of transition) suggests that a more comprehensive understanding of the events should be an immediate future goal for the research community, at large.

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