Library · Materials, chemistry & fabrication
What Thermal Annealing & Calcination got wrong, from 51 theses
Summary written by a model from the records below: The records demonstrate various failure modes encountered during thermal annealing and calcination processes across diverse materials systems. Unsuccessful outcomes frequently stemmed from unwanted phase transformations, thermal stress cracking, morphology degradation from excessive sintering, and the loss of electrical or mechanical integrity. These records come from graduate theses, 2021 to 2026, each labeled with its degree where the repository states it, and each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Plus 10 problems the authors left open, listed at the end.
Failure modes, by theses reporting them
Select a mode to jump to its records.
Unwanted phase transformations, phase segregation, and thermal decomposition undermine material integrity
Thermal annealing triggered detrimental phase transitions, unwanted crystallization, and segregation into secondary phases or elemental clusters. These structural changes compromised lattice purity, altered bandgaps, and induced thermal decomposition across thin films and bulk alloys.
Tried and failed
thermal annealing of vapor-deposited thin films applied to formamidinium lead iodide perovskite films. Reason: annealing caused transformation into mixed hexagonal polytypes rather than phase-pure cubic phase
Deposition of Metal Halide Perovskite Thin Films by Thermal Evaporation · Georgia Tech · PhD
Tried and failed
thermal annealing to remove polymer binder applied to printed transition metal dichalcogenide electrodes. Outcome: worse than baseline. Reason: annealing caused phase transition from conducting 1T' to semiconducting 2H phase via delithiation
Direct ink writing of two-dimensional materials for electrochemical energy storage devices · Imperial · PhD
Considered and rejected
Considered and rejected: Rejected post-growth thermal annealing of the completed heterostructure because it weakened both 2D and 3D crystal peaks and induced halide phase segregation.
Investigation of 2D Hybrid Organic-Inorganic Perovskite Thin Films Deposited by RIR-MAPLE for Heterostructure Integration · Duke · Doctorate
Considered and rejected
Considered and rejected: Rejected post-synthesis next-day annealing in favor of single-step in-situ annealing because it yielded poor crystallinity and an XRD peak shift of +0.24 degrees.
Enhancing the Electron Transfer at Electrochemical Interfaces by Spinel Oxide-Nanostructures · Politecnico di Torino · PhD
Considered and rejected
Considered and rejected: Rejected annealing nano-K0.3MoO3 above 200 °C for sintering due to phase instability.
Electronic structure of low-dimensional and strongly correlated materials studied with resonant inelastic X-ray scattering · Boston University · PhD
Tried and failed
thermal annealing to induce recrystallization from melt applied to metal-organic coordination polymer melts. Reason: extremely slow crystallization kinetics and high glass-forming ability cause permanent vitrification upon cooling
Network-Forming Metal–Organic Liquids and Glasses · Harvard · PhD
Tried and failed
thermal homogenization based on published phase diagrams applied to ternary metal alloy system. Reason: annealing at literature temperature precipitated unwanted brittle intermetallic secondary phases
Design of Superelastic Secondary-Phase-Toughened Alloys · MIT · PhD
Tried and failed
high-temperature annealing to homogenize multi-principal component alloys applied to equimolar refractory multi-element alloy. Reason: positive atomistic mixing energy causing persistent elemental segregation and multiphase retention despite extended annealing
Tried and failed
vacuum post-annealing of mechanochemically synthesized materials applied to halide solid electrolytes. Outcome: unstable. Reason: vacuum annealing induced thermal decomposition and unwanted phase transitions
Understanding ion transport in halide solid electrolytes with varying mobile species · Imperial · PhD
Considered and rejected
Considered and rejected: Rejected standard furnace annealing (220–240 °C) for amorphous synthesis because it formed crystalline spinel phases rather than amorphous oxides.
Crystalline and amorphous cobalt-based metal oxides for water oxidation reaction – structure, composition, morphology and electrochemical · York University · PhD
Tried and failed
thermal annealing to induce reverse phase transition applied to encapsulated layered chalcogenide thin films. Outcome: unstable. Reason: high temperatures caused sample degradation before triggering the reverse phase transition
Phase and defect control of 2D-material based memory devices by scanning tunneling microscopy · UT Austin · PhD
Tried and failed
high-temperature pre-annealing of sublayer coatings applied to optical interference multilayer coatings. Outcome: worse than baseline. Reason: phase separation within the sublayer increased mechanical loss and thermal noise
Coating Thermal Noise in Gravitational-Wave Detectors · MIT · PhD
Considered and rejected
Considered and rejected: Rejected high-temperature PVDF annealing (90–150 °C) because elevated temperatures promoted thermodynamically stable α-phase over electroactive β-phase
Roll-to-Roll processable organic thin film transistor based circuits and their sensory application · Oxford · PhD
Considered and rejected
Considered and rejected: Rejected thermal annealing above 350 °C (specifically 350 °C and 400 °C) because it triggered phase transformation of SnS2 into orthorhombic SnS, collapsing the bandgap to ~1.3 eV and breaking exciton resonance.
Enhanced Raman scattering on 2D vdW materials · Boston University · PhD
Thermal processing impairs electrical, optical, and contact characteristics in semiconductor devices
Heat treatments caused dopant deactivation, increased contact resistance, and degraded surface passivation in active semiconductor layers. Annealing also induced interfacial defect aggregation and carrier extraction barriers, leading to lower photovoltaic efficiency and reduced photodetector responsivity.
Tried and failed
slow cooling during post-annealing thermal processing applied to inorganic perovskite solar cells. Outcome: worse than baseline. Reason: oxygen-induced surface p-doping created a charge extraction barrier at the electron transport interface
Formation pathways and phase behaviour of CsPbI2Br: toward stable and reproducible solar sells · Imperial · PhD
Tried and failed
rapid thermal annealing for ohmic contact formation applied to p-doped 2D wide-bandgap semiconductors. Outcome: worse than baseline. Reason: annealing degraded electrical contact performance instead of improving ohmic behavior
Hexagonal boron nitride for deep UV applications · Georgia Tech · PhD
Tried and failed
thermal annealing in non-ultra-dry ambient atmosphere applied to semiconductor ion-implantation dopant activation. Outcome: worse than baseline. Reason: trace water vapor above baseline levels causes dopant deactivation and increases sheet resistance
Thermally Induced Dopant Activation, Dopant Deactivation, and Polymorphic Phase Transformations in Ga2O3 · Cornell · PhD
Tried and failed
post-deposition thermal annealing for contact resistance reduction applied to monolayer 2D semiconductor metal contacts. Outcome: worse than baseline. Reason: did not improve contact resistance and risked exciton localization around intrinsic structural defects
Exciton-Trion-Polaritons in Two-Dimensional Transition-Metal Dichalcogenides · Cornell · PhD
Lost to a baseline
Single-step air-annealed CsPbBr3 cells at 320 °C produced lower Voc and fill factor than two-step 320 °C/300 °C annealing.
Cesium based all inorganic perovskite solar cells · Iowa State · PhD
Lost to a baseline
Post-optimization thermal annealing of CZTS at 50 °C for 5 min decreased TAS charge transfer relative to unannealed washed films
Materials and deposition methods for the manufacture of low-cost solar cells · Imperial · PhD
Lost to a baseline
AuNPs/Gr/Si photodetectors fabricated by thin film annealing showed lower responsivity than bare Gr/Si photodetectors in the UV band (<400 nm) and IR band (>800 nm).
Research on graphene/silicon Schottky junction based photodetector · Politecnico di Torino · PhD
Considered and rejected
Considered and rejected: Rejected post-deposition thermal annealing for PbI2-route MAPbI3 co-evaporated films because it degraded PV performance without morphology benefit.
Control of electronic properties of metal halide perovskites through vacuum co-deposition · Oxford · PhD
Considered and rejected
Considered and rejected: Thermal annealing (>70 °C) of PCE10:PC71BM layers was rejected because it degrades J-V characteristics by lowering shunt resistance and reducing EQE.
LOW-NOISE ORGANIC PHOTODIODES WITH NEAR-INFRARED SENSITIVITY · Georgia Tech · PhD
Considered and rejected
Considered and rejected: Pre-annealing the (i)a-Si:H layer above 250 °C (e.g., 260–275 °C) was rejected for standard fabrication because it inhomogeneously degrades baseline surface passivation.
Considered and rejected
Considered and rejected: Rejected post-metallization thermal contact annealing because metal-TMD junctions do not reliably improve and annealing causes exciton localization at defect sites.
Exciton-Trion-Polaritons in Two-Dimensional Transition-Metal Dichalcogenides · Cornell · PhD
Tried and failed
post-fabrication thermal annealing to heal interface defects applied to 2D material van der Waals heterostructures. Outcome: worse than baseline. Reason: annealing caused interfacial bubbles and defects to aggregate and enlarge rather than heal
Interlayer Excitons in Atomically Thin van der Waals Semiconductor Heterostructures · Harvard · PhD
Tried and failed
solvent vapour annealing applied to conjugated polymer ionic liquid blends. Outcome: worse than baseline. Reason: induced phase segregation and fibril clustering, disrupting the interconnected conductive network and reducing current
Molecular-structure dependent polaron formation in conjugated polymers – fundamentals and applications · Imperial · PhD
Excessive sintering and grain coarsening disrupt nanostructure morphology and surface area
Elevated temperatures or prolonged annealing durations caused uncontrolled particle agglomeration, excessive grain growth, and severe sintering. These morphological changes led to substantial losses in specific surface area, disrupted particle uniformity, and reduced electrochemical activity.
Tried and failed
low-temperature calcination to remove organic templates applied to mesoporous metal nanoparticle synthesis. Outcome: worse than baseline. Reason: lower temperature required excessively long annealing times and resulted in significantly reduced specific surface area
Exploring the Mechanisms of the Early Stages of the Formation of Silver Nanoparticles and the Role of Organic Additives · Leibniz Universität Hannover · PhD
Considered and rejected
Considered and rejected: Rejected non-vacuum hotplate annealing for perovskite prints due to multi-nucleation forming core/satellite crystal structures.
Advancing Additive Nanomanufacturing of Quantum Optoelectronics · University of Washington · PhD
Tried and failed
extended thermal annealing duration applied to porous metal nanoparticle synthesis. Outcome: worse than baseline. Reason: prolonged heating caused excessive sintering, significantly reducing specific surface area
Exploring the Mechanisms of the Early Stages of the Formation of Silver Nanoparticles and the Role of Organic Additives · Leibniz Universität Hannover · PhD
Tried and failed
thermal annealing at elevated temperatures applied to porous metal-organic precursor monoliths. Outcome: worse than baseline. Reason: excessive sintering reduced the specific surface area
Exploring the Mechanisms of the Early Stages of the Formation of Silver Nanoparticles and the Role of Organic Additives · Leibniz Universität Hannover · PhD
Tried and failed
post-processing annealing heat treatment applied to extruded aluminium profiles. Outcome: worse than baseline. Reason: annealing caused grain growth, reducing both ultimate tensile strength and elongation compared to as-extruded condition
Lost to a baseline
Mass activity of dealloyed PdMn/C (0.30 mA/μgPd) was lower than dealloyed PdNi/C (0.37 mA/μgPd) due to large particle size from high-temperature annealing.
ELECTROCATALYSTS AND POLYMER ELECTROLYTES FOR ANION EXCHANGE MEMBRANE FUEL CELLS · Cornell · PhD
Considered and rejected
Considered and rejected: Rejected high-temperature annealing at 800 °C for AuAg nanostructures because it ruined the designed shape into an ill-defined blubbery geometry.
Fabrication and applications of AuAg alloy metasurfaces and hybrid metal dielectric nanoantennas · EPFL · PhD
Considered and rejected
Considered and rejected: Discarded 3-step solid-state reaction synthesis due to high processing temperatures, long annealing times, and excessive grain growth causing high thermal conductivity.
Development of Cu2SnS3 based thermoelectric materials and devices · University of Trento · PhD
Considered and rejected
Considered and rejected: Direct single-step high-temperature reducing annealing (>600 °C) was rejected because it degraded NT morphology; a two-step double annealing (O2 at 500 °C then 2% H2/N2 at 600 °C) was used to form Magnéli phases.
Processing, Structure, and Electrochemical Behavior of Anodically Formed Titanium Oxide Nanotubes for the Electrooxidation of Pathogens · University of Nevada, Reno · PhD
Thermal expansion mismatch and high temperatures cause cracking, delamination, and substrate damage
Thermal expansion differences between bonded wafers, coatings, and underlying substrates induced mechanical stress that resulted in severe cracking and delamination during heating. High annealing temperatures also directly degraded, deformed, or induced unwanted oxygen diffusion from temperature-sensitive glass, polymer, and flexible substrates.
Considered and rejected
Considered and rejected: Discarded thermal annealing (>450°C to 900°C) for forming Cu/Zn nanoparticles due to substrate thermal degradation constraints.
Innovative smart composite coatings endowing antimicrobial properties to several materials · Politecnico di Torino · PhD
Considered and rejected
Considered and rejected: Rejected direct high-temperature annealing (>500 °C) on glass/flexible substrates due to thermal degradation and substrate-induced oxygen diffusion.
Progress on 2D-MoS2: development of a scalable fabrication method and demonstration of an X-ray detector · University of Trento · PhD
Tried and failed
direct wafer bonding with high-temperature annealing applied to heterogeneous materials with thermal mismatch. Outcome: unstable. Reason: thermal expansion coefficient mismatch caused mechanical cracking during annealing
A Novel Heterogeneously Integrated Photonic Platform for Optical Interconnects · Georgia Tech · PhD
Tried and failed
direct wafer bonding with thermal annealing applied to heterogeneous crystalline substrates. Outcome: unstable. Reason: thermal expansion mismatch between substrates caused cracking during post-bonding annealing
Towards microwave-to-optical quantum transduction with barium titanate/strontium titanate integrated photonics · EPFL · PhD
Tried and failed
thermal annealing of high-stress metallic thin films applied to deposited electrical contact test structures. Outcome: unstable. Reason: high as-deposited residual stress caused film rupture and delamination during heating
Effects of Crystalline Anisotropy on Solid-state Dewetting · MIT · PhD
Considered and rejected
Considered and rejected: Thermal annealing of samples post-laser scribing was rejected because repeated scribing and heating caused the glass substrates to crack reliably.
Unraveling the Reconfiguration Dynamics of Silver Nanowire Networks under Electrothermal Stress · MIT · PhD
Tried and failed
high-temperature thermal annealing applied to heterogeneous thin film on substrate. Outcome: unstable. Reason: thermal expansion mismatch causes film cracking, delamination, ion out-diffusion, and surface degradation
Integrated lithium niobate photonics and applications · Harvard · PhD
Tried and failed
sequential thin film deposition and high-temperature annealing applied to oxide coatings on silicon substrates. Reason: severe thermal expansion coefficient mismatch caused substrate cracking during high-temperature annealing
Fluorescent Materials and Thin Film Coatings for Temperature Sensing Applications · Georgia Tech · PhD
Annealing induces mechanical softening, loss of yield strength, and structural deterioration
Heat application relaxed internal stresses and caused excessive malleability, leading to unintended deformation and reduced yield or tensile strength in bulk metals and polymers. In other instances, thermal processing weakened structures, causing lower biaxial strength, component crumbling, or electrode degradation.
Tried and failed
thermal annealing before hydrophobic coating deposition applied to porous gas-diffusion electrodes. Outcome: worse than baseline. Reason: pre-treatment heat application degraded the electrode structure and reduced overall electrochemical performance
Electrocatalyst performance at the gas/Electrolyte interface under high mass transport conditions · Imperial · PhD
Lost to a baseline
PEEK Young's modulus under direct annealing (DA) was inferior compared to traditional post-oven annealing (PA).
3D printing of semi-crystalline high-performance polymers for localized production · Politecnico di Torino · PhD
Considered and rejected
Considered and rejected: Rejected silver (Ag) resistive microheaters due to low melting temperature causing deformation of plasmonic meta-atoms during repeated annealing.
Dynamic Nanophotonic Structures Leveraging Chalcogenide Phase-Change Materials · Georgia Tech · PhD
Tried and failed
thermal annealing to relieve residual mechanical stress applied to metallic substrate formers. Reason: annealing reduced material yield strength, causing excessive malleability and unintended deformation during subsequent handling
Characterizing and using defects in high-temperature superconductor cables and magnets · MIT · Doctorate
Tried and failed
post-fabrication annealing heat treatment applied to micrometer-scale additively manufactured titanium lattice structures. Reason: microstructural phase transformation failed to provide sufficient ductility to prevent brittle layer-by-layer strut crumbling
Hierarchical Strengthening of Polycrystal-Inspired Lattice Materials · Imperial · PhD
Tried and failed
strain-assisted displacive phase transformation via boundary pre-enrichment applied to heavily deformed maraging steel alloys. Outcome: worse than baseline. Reason: matrix strain hardening and defect accumulation pinned phase boundary mobility during low-temperature annealing
High-strength transformation-induced plasticity steels with reverted interlath austenite · MIT · PhD
Lost to a baseline
Annealing the milled TNM bulk material for 100 h at 850 °C in ambient air caused a biaxial strength reduction from 1984 ± 190 MPa to 1209 ± 71 MPa (loss of ~775 MPa)
High-temperature oxidation resistant coatings concepts for γ-TiAl based alloys · TU Wien · PhD
Considered and rejected
Considered and rejected: Discarded high-temperature thermal annealing (~500 °C) of Si3N4 thin-film membranes because it relaxes material stress (by ~50% at 200 °C) and causes HfO2 crystallization, preventing wet-chemical removal.
Room-Temperature Quantum Optomechanics and Free-Electron Quantum Optics · EPFL · PhD
Thermal treatments cause material loss through evaporation and desorption of volatile constituents
High processing temperatures caused significant desorption of lattice elements and premature evaporation of absorber layers or crystalline additives. This volatilization altered intended chemical compositions and harmed photovoltaic parameters including open-circuit voltage and fill factor.
Considered and rejected
Considered and rejected: Rejected post-growth high-temperature annealing (>250 °C) because it leads to significant desorption of Zn from the Zn3P2 lattice and degrades thin-film composition.
Zn3P2 as an earth-abundant photovoltaic material: from growth to device · EPFL · PhD
Tried and failed
intermediate annealing before chemical conversion applied to two-step thin-film semiconductor synthesis. Outcome: worse than baseline. Reason: premature volatilization and loss of crystalline modifier additive degraded device open-circuit voltage and fill factor
Scalable Perovskite Thin-Film Photovoltaics · MIT · PhD
Left open by the authors
Problems the authors named and did not get to.
Left open
Determine whether reduced total NV center concentration after 1250 °C annealing stems from mobile detrimental species or thermochromic charge-transfer effects. Blocker: Requires diamond sample fabrication, high-temperature annealing furnace, and photoluminescence spectroscopy equipment.
High-Sensitivity Nitrogen-Vacancy Center Magnetometry: from DC to GHz · MIT · PhD
Left open
Implement a post-annealing step to reduce amorphous regions and improve discharge capacity in MnO thin films. Blocker: Requires a physical materials synthesis and characterization laboratory with annealing equipment and electrochemical testing apparatus.
Mapping chemical, ionic and electronic properties of high capacity cathode materials for lithium-ion batteries · Oxford · PhD
Left open
Determine activation energy and mechanisms for dopant deactivation and reactivation under controlled PO2 using calibrated heating rates and staged anneals to saturation. Blocker: Requires a physical materials synthesis/annealing furnace with controlled PO2 environment and experimental characterization equipment.
Thermally Induced Dopant Activation, Dopant Deactivation, and Polymorphic Phase Transformations in Ga2O3 · Cornell · PhD
Left open
Optimize post-process thermal annealing cycles for SLM soda-lime silica glass structures to enhance optical translucency while retaining geometric accuracy. Blocker: Requires physical SLM hardware, high-temperature annealing furnaces, and optical/dimensional measurement equipment.
Investigations into glass additive manufacturing by selective laser melting and directed energy deposition · Nottingham · PhD
Left open
Optimize annealing parameters for Inconel 600 to prevent abnormal grain growth. Blocker: Requires materials laboratory equipment for metallurgical heat treatment, annealing, and microstructure characterization
Bromide induced corrosion of stainless steels and Ni-based alloys · Imperial · PhD
Left open
Design thin layer-like precipitation phases that nucleate at mechanical stacking faults during low-temperature annealing in metastable FCC alloys. Blocker: Requires materials synthesis, heat treatment equipment, and experimental metallography characterization facilities.
Overcoming the limits of strain-induced martensitic transformation in metastable face-centered cubic alloys · MIT · Doctorate
Left open
Systematically vary furnace annealing temperatures and soak times to increase the CuAg alloy fraction beyond 2%. Blocker: Requires a physical materials synthesis laboratory and furnace annealing apparatus
Gas hydrates and Metal Nanoparticles for the Energy Transition and Environmental Applications · University of Camerino · PhD
Left open
Systematically decouple particle size, misfit strain, and transformation temperature effects by adjusting annealing protocols, vanadium matrix content, and nickel-to-titanium ratios. Blocker: Requires a physical metallurgy lab, alloy synthesis equipment, heat treatment furnaces, and in-situ characterization tools
Design of Superelastic Secondary-Phase-Toughened Alloys · MIT · PhD
Left open
Anneal synthesized Zr-based MAX phases at intermediate temperatures to experimentally test predicted decomposition into intermetallics and carbides. Blocker: Requires a physical materials synthesis and high-temperature annealing laboratory.
A theoretical study of the stability of Zr-Al-C and Ti-Al-C MAX phases · Imperial · PhD
Left open
Optimize the flash lamp annealing process using sub-second multi-flash annealing to synthesize phase-pure cubic FeGe thin films. Blocker: Requires a physical materials synthesis and annealing laboratory (sputtering, flash lamp annealing system, XRD/magnetometry characterization).
Synthesis, structural and magnetic characterization of thin films of the chiral magnets CoZnMn and FeGe · EPFL · PhD
Who has worked on this
Authors of the public theses cited on this page, most-cited first.
- Dilafruz Allanazarova · Leibniz Universität Hannover · PhD · 2026
Exploring the Mechanisms of the Early Stages of the Formation of Silver Nanoparticles and the Role of Organic Additives - Katie Gann · Cornell · PhD · 2024
Thermally Induced Dopant Activation, Dopant Deactivation, and Polymorphic Phase Transformations in Ga2O3 - Jaclyn L. Cho · MIT · PhD · 2021
Design of Superelastic Secondary-Phase-Toughened Alloys - Okan Koksal · Cornell · PhD · 2021
Exciton-Trion-Polaritons in Two-Dimensional Transition-Metal Dichalcogenides - Richard Kim · Georgia Tech · PhD · 2026
Fluorescent Materials and Thin Film Coatings for Temperature Sensing Applications - André Perepeliuc · Georgia Tech · PhD · 2025
Hexagonal boron nitride for deep UV applications - Esra Alhabshi · Imperial · PhD · 2025
Formation pathways and phase behaviour of CsPbI2Br: toward stable and reproducible solar sells - Nicholas Demos · MIT · PhD · 2025
Coating Thermal Noise in Gravitational-Wave Detectors - Kit Barker · Imperial · PhD · 2025
Understanding ion transport in halide solid electrolytes with varying mobile species - MALLIKARJUN MADAGALAM · Politecnico di Torino · PhD · 2025
Enhancing the Electron Transfer at Electrochemical Interfaces by Spinel Oxide-Nanostructures - Nicholas Russo · Boston University · PhD · 2025
Electronic structure of low-dimensional and strongly correlated materials studied with resonant inelastic X-ray scattering - Gregory Guymon · University of Washington · PhD · 2025
Advancing Additive Nanomanufacturing of Quantum Optoelectronics
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