One of the most exciting directions in modern ceramic science is the development of high-entropy nanoceramics, a new class of materials that challenges the traditional idea that ceramics must be made from one or two major elements. In high-entropy ceramics (HECs) and high-entropy oxides (HEOs), five or more elements are mixed in nearly equal proportions, resulting in high configurational entropy that stabilises the material into a single-phase solid solution and prevents phase separation. A widely cited study by Zhang and Reece (2019) explains how this entropy-driven stabilisation allows precise tuning of dielectric, electronic and thermal behaviour through atomic-scale disorder . A striking demonstration of this concept comes from the rock-salt high-entropy oxide (Mg,Co,Ni,Cu,Zn)O, where 10–30 nm grains maintained a stable single-phase structure even above 1000 °C while exhibiting a dielectric constant of ~145 at 1 MHz, confirming the exceptional thermal and functional stability that entropy engineering can deliver (Rost et al.,2015). More recently, Verma et al. (2023) further showed that high-entropy ceramics possess remarkable hot hardness, corrosion resistance and high-temperature durability, highlighting their potential for extreme-environment applications in fields such as aerospace, defence and energy conversion.

Alongside new compositions, researchers are also reimagining how nanoceramics are processed. Traditional sintering above 1000 °C can destroy nanoscale features and consumes significant energy, so low-temperature routes have become an important area of development. Among these, the Cold Sintering Process (CSP) has emerged as a breakthrough technique that uses a small amount of transient liquid—often water—combined with moderate pressure to densify ceramics at temperatures below 300–400 °C, rather than the high temperatures required in conventional sintering. CSP has been successfully applied to functional ceramics and ceramic–polymer composites, enabling dense microstructures to be achieved at drastically lower temperatures while preserving nanoscale grain size and reducing energy demand (Guo et al., Advanced Materials, 2016). A related emerging technique is Flash Sintering (FS), in which an electric field is applied during heating to trigger densification within seconds. Beyond lowering energy consumption, FS has attracted attention because it can freeze in non-equilibrium defect structures that may improve ionic transport or catalytic behaviour.

Advances in nanoceramics are also reshaping additive manufacturing (3D printing). By formulating ceramic slurries or “inks” with carefully controlled particle loading and rheology, researchers can print intricate architectures that would be extremely difficult or impossible to shape by conventional machining. Comprehensive reviews by Zocca et al. (2015) show how a variety of additive manufacturing methods — including vat photopolymerisation, robocasting, binder jetting and directed energy deposition — have been adapted to oxide ceramics such as alumina and zirconia, enabling both porous scaffolds and near-dense structural parts to be fabricated layer by layer. A more recent historical review of structural ceramic additive manufacturing reports that fully dense alumina–zirconia–yttria eutectic ceramics produced by directed energy deposition can achieve eutectic spacing of about 100 nm, with hardness around 17.15 GPa and fracture toughness about 4.79 MPa·m¹ᐟ², demonstrating that additively manufactured ceramics can combine fine-scale microstructures with mechanical properties comparable to conventionally processed structural ceramics (Pelz et al., 2021). These developments indicate that as processing and feedstock design improve, 3D-printed ceramic components will increasingly be used for complex, high-performance parts in applications such as heat exchangers, protective structures and specialised substrates.

Looking ahead, the rapidly evolving field of nanoceramics is centred on several major research priorities: designing interfaces and grain boundaries to optimise ion and electron transport, using machine learning to explore the vast composition space of high-entropy ceramics, integrating multiple functionalities (ferroelectric, magnetic, catalytic and thermal) into the same ceramic platform and developing sustainable low-carbon manufacturing routes for industrial scale-up. All these developments show that nanoceramics are no longer just an improvement over traditional ceramics — they represent a new paradigm for engineering matter at the atomic and nanoscale to achieve properties that were once thought impossible.