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Microwave-induced thermoacoustic tomography (MITAI) has found diversified applications in biomedical related disciplines. This work reports a novel MITAI modality to homogenize the microwave power deposition in the sample and improve the image quality for small animal imaging via scanning orthogonal polarization (SOP) excitation. Although circular polarization excitation has been reported to enhance MITAI, we perform some simulation works using realistic breast phantoms to prove that the homogeneity of microwave power distribution in the phantoms using orthogonal polarization excitation is comparable to that using circular polarization excitation. Compressive sensing is also applied to enhance the time efficiency of the system. Experiments applying a mouse and a frog sample are conducted. The results indicate that the SOP excitation mechanism can completely reveal the structure of the small animals due to improved power homogeneity. The proposed MITAI-SOP technique is superior to circularly polarized antenna (CPA) based modality since the former avoids the deficiency of CPA in bandwidth, power capacity and efficiency. This work presents a practical and easy-to-implement paradigm for high-quality imaging of small animals and big biological samples using MITAI.

There is a great need in temperature monitoring in biomedical applications. The current available temperature measurement techniques have some deficiencies in noninvasiveness, applicability, sensitivity and resolution. Microwave-induced thermoacoustic tomography (MITAT) has found diversified applications in biomedical related disciplines. It has been shown that MITAT can be used to estimate the temperature in a noninvasive manner. However, the applicability of the technique is still limited. This work presents experimental demonstration of two-dimensional (2-D) temperature detection of biological samples based on compressive TAT, referred to as MICTAT. Detailed principle of the method is established. A phantom sample and a biological sample are tested by experiments and 2-D temperature maps are obtained. This work provides a new route of getting 2-D temperature maps of biological samples and may find many applications in biomedical related areas.

Microwave-induced thermoacoustic tomography (MITAT) is suitable for detecting foreign bodies (FBs) in human body due to the sufficient microwave contrast between the FBs and surrounding human tissues. But detection of both hot and cold FBs by the same modality has not been demonstrated. In addition, traditional widely used imaging algorithms for MITAT requires highly intensive measurements, which is not cost-effective or time-efficient. This work reports the application of a low-cost compressive thermoacoustic tomography (CTAT) system for the detection of both hot and cold FBs embedded in tissues, referred to as FBD. We give detailed description of the theory of MITAT and CTAT. We show experimental demonstrations using different shaped metallic samples as the hot FBs and glass and wood samples as the cold FBs. We achieve successful detection of all the hot and cold FBs embedded in different tissues. The CTAT-FBD method is a new paradigm promising for a bunch of diagnosis or sensing applications. It is also possible to build a portable system for this technique.

In this study, LiMn2-x Ti x O4 cathode materials were synthesized by a simple one-step hydrothermal method, and the effects of Ti doping on the sample structure and electrochemical properties were examined. The results indicated that Ti doping did not affect the spinel structure of LiMn2O4, and no other hybrid phases were produced. Furthermore, appropriate doping with Ti improved the particle uniformity of the samples. The electrochemical performance results showed that LiMn1.97Ti0.03O4 exhibited much better cycling performance than the undoped sample. The discharge capacity of LiMn1.97Ti0.03O4 reached 136 mAh g-1 at 25 °C at 0.2C, and the specific capacity reached 106.2 mAh g-1 after 300 cycles, with a capacity retention rate of 78.09%. Additionally, the specific capacity of LiMn1.97Ti0.03O4 was 102.3 mAh g-1 after 100 cycles at 55 °C, with a capacity retention rate of 75.44%. The Ti-doped samples thus exhibited an impressive high-rate performance. The discharge capacity of LiMn2O4 was only 31.3 mAh g-1 at 10C, while the discharge-specific capacity of LiMn1.97Ti0.03O4 reached 73.4 mAh g-1. Furthermore, to assess the higher Li+ diffusion coefficient and lower internal resistance of the Ti-doped samples, cyclic voltammetry and impedance spectra data were obtained. Our results showed that Ti doping enhanced the crystal structure of LiMn2O4 and improved Li+ diffusion, resulting in significant improvements in the cycling and rate performance of Ti-doped samples.

Deformations triggered by body heat are desirable in the context of shape-morphing applications because, under the majority of circumstances, the human body maintains a higher temperature than that of its surroundings. However, at present, this bioenergy-triggered action is primarily limited to soft polymeric networks. Thus, herein, the programming of body temperature-triggered deformations into rigid azobenzene-containing liquid crystalline polymers (azo-LCPs) with a glass-transition temperature of 100 °C is demonstrated. To achieve this, a mechano-assisted photo-programming strategy is used to create a metastable state with room-temperature stable residual stress, which is induced by the isomerization of azobenzene. The programmed rigid azo-LCP can undergo large-amplitude body temperature-triggered shape changes within minutes and can be regenerated without any performance degradation. By changing the programming photomasks and irradiation conditions employed, various 2D to 3D shape-morphing architectures, including folded clips, inch-worm structures, spiral structures, and snap-through motions are achieved. When programmed with polarized light, the proposed strategy results in domain-selective activation, generating designed characteristics in multi-domain azo-LCPs. The reported strategy is therefore expected to broaden the applications of azo-LCPs in the fields of biomedical and flexible microelectronic devices.

We report a one-pot synthesis method based on two-step sequential thiol–ene reactions for the facile preparation of azobenzene-interconnected photoresponsive polymers (azo-ICPRPs). In the first step, block-length-controlled azobenzene prepolymers (azo-prepolymers) are prepared in situ in a molten reaction mixture by using the nucleophile-catalyzed chemoselective thiol-Michael reaction. In the second step, the formed azo-prepolymers are further crosslinked with ultraviolet (UV)-transparent monomers by a free radical-initiated thiol–ene “click” reaction, yielding a crosslinked polymer system with rubbery storage moduli (Er) ranging from 3.6 to 6.7 MPa and glass transition temperatures (Tg) ranging from 21 to 28 °C. The interconnection of azobenzene moieties in azo-ICPRPs is found to greatly amplify the photo-actuation performance. Compared to single-step polymerized polymers with the same monomer composition, azo-ICPRPs with long-block-length showed up to 7 times higher photostrains, with 50 times faster kinetics. Consequently, the specific actuation work and power output during each stroke were also greatly amplified by the interconnection of azobenzene. The maximum measured specific stroke work and power output under 15 mW cm−2 UV activation were 121.3 kJ m−3 and 34 W kg−1, respectively, which are comparable to those for skeletal muscles.

Objective: As a newly developed technique, focused microwave breast hyperthermia (FMBH) can provide accurate and cost-effective treatment of breast tumors with low side effect. A clinically feasible FMBH system requires a guidance technique to monitor the microwave power distribution in the breast. Compressive thermoacoustic tomography (CTT) is a suitable guidance approach for FMBH, which is more cost-effective than MRI. However, no experimental validation based on a realized FMBH-CTT system has been reported, which greatly hinders the further advancement of this novel approach. Methods: We developed a preclinical system prototype for the FMBH-CTT technique, containing a microwave phased antenna array, a microwave source, an ultrasound transducer array and associated data acquisition module. Results: Experimental results employing homogeneous and inhomogeneous breast-mimicking phantoms demonstrate that the CTT technique can offer reliable guidance for the entire process of the FMBH. In addition, small phase noises do not deteriorate the overall performance of the system prototype. Conclusion: The realized preclinical FMBH-CTT system prototype is capable for noninvasive, accurate and low-side-effect breast tumor treatment with effective guidance. Significance: The experimentally validated FMBH-CTT system prototype provides a feasible paradigm for CTT guided FMBH, establishes a practical platform for future improvement of this technique, and paves the way for potential clinical translation.

The Hot Universe Baryon Surveyor (HUBS) is a satellite concept proposed in China to address the so-called “missing baryon problem”, which has serious implications on the formation and evolution of galaxies. At the heart of HUBS there is a high-resolution soft X Ray spectrometer based on transition-edge sensors operating below 100 mK. A cooling system is needed to provide such a low-temperature environment. It necessarily consists of a precooling stage and a cold stage. The cold stage could be enabled by an adiabatic demagnetization refrigerator (ADR). Because an ADR could be operated without gravity’s assist and has no refrigerant consumption, it is a good candidate for satellite mission like HUBS. For HUBS, the ADR will be employed to cool the detector down to below 100 mK from the precooling stage (at about 4K), which is enabled by mechanical pulse tube refrigerators. ADR for HUBS is now under development in our lab. The key technologies of building an ADR including growth of paramagnetic salt pill crystals, gas-gap heat switch are under development. A preliminary design of the ADR is completed and the design parameters are optimized. In this paper, we report on the status of the development.

Nastic movements in plants that occur in response to environmental stimuli have inspired many man-made shape-morphing systems. Tendril is an exemplification serving as a parasitic grasping component for the climbing plants by transforming from a straight shape into a coiled configuration via the asymmetric contraction of internal stratiform plant tissues. Inspired by tendrils, this study using a three-dimensional (3D) printing approach developed a class of soft grippers with preprogrammed deformations being capable of imitating the general motions of plant tendrils, including bending, spiral, and helical distortions for grasping. These grippers initially in flat configurations were tailored from a polymer-paper bilayer composite sheet fabricated via 3D printing a polymer on the paper substrate with different patterns. The rough and porous paper surface provides a printed polymer that is well-adhered to the paper substrate which in turn serves as a passive strain-limiting layer. During printing, the melted polymer filament is stretched, enabling the internal strain to be stored in the printed polymer as memory, and then it can be thermally released, which will be concurrently resisted by the paper layer, resulting in various transformations based on the different printed geometries. These obtained transformations were then used for designing grippers to grasp objects with corresponding motions. Furthermore, a fully equipped robotic tendril with three segments was reproduced, where one segment was used for grasping the object and the other two segments were used for forming a tendril-like twistless spring-like structure. This study further helps in the development of soft robots using active polymer materials for engineered systems.

We compare the actuation speeds of the azobenzene-doped nematic liquid crystal polymer (azo-LCP) by examining its activation mechanisms: photoisomerization and trans–cis–trans reorientation (TCTR) (also known as Weigert effect). Both experiments and modeling are carried out in this study to compare the speed of bending and contraction acting on azo-LCP. We identify that the TCTR-based photobending of azo-LCP generated less than half the photostrain in a unit cell than that in the photoisomerization case but involves a larger azo-LCP thickness in triggering photodeformation. Because photodeformation occurs in a deeper region than that in the photoisomerization case, the TCTR-based photobending of azo-LCP exhibits a faster bending speed than the photoisomerization-based photobending of azo-LCP, even though less strain is generated in the TCTR case.

Combining experimental and theoretical studies, we investigate the role of R-site (R = Y, Sm, Bi) element on the phase formation and thermal stability of R2(Mn1−xFex)4O10−δ (x = 0, 0.5, 1) mullite-type oxides. Our results show a distinct R-site dependent phase behavior for mullite-type oxides as Fe is substituted for Mn: 100% mullite-type phase was formed in (Y, Sm, Bi)2Mn4O10; 55% and 18% of (Y, Sm)2Mn2Fe2O10−δ was found when R = Y and Sm, respectively, for equal Fe and Mn molar concentrations in the reactants, whereas Bi formed 54% O10- and 42% O9-mixed mullite-type phases. Furthermore, when the reactants contain 100% Fe, no mullite-type phase was formed for R = Y and Sm, but a sub-group transition to Bi2Fe4O9 O9-phase was found for R = Bi. Thermogravimetric analysis and density functional theory (DFT) calculation results show a decreasing thermal stability in O10-type structure with increasing Fe incorporation; for example, the decomposition temperature is 1142 K for Bi2Mn2Fe2O10−δ vs. 1217 K for Bi2Mn4O10. On the other hand, Bi2Fe4O9 O9-type structure is found to be thermally stable up to 1227 K. These findings are explained by electronic structure calculations: (1) as Fe concentration increases, Jahn–Teller distortion results in mid band-gap empty states from unstable Fe4+ occupied octahedra, which is responsible for the decrease in O10 structure stability; (2) the directional sp orbital hybridization unique to Bi effectively stabilizes the mullite-type structure as Fe replaces Mn.

We propose a new model for predicting the trans-cis-trans reorientation (TCTR)-based photodeformation of the azobenzene-doped liquid-crystal polymer (azo-LCP). The model was validated through the results of a bi-directional photobending experiment performed at various temperatures and mole ratios of the azobenzene monomer within the azo-LCP. Through both numerical and experimental investigations, we found that the photobending curvature of the azo-LCP shows a maximum point at certain temperatures, but only shows a proportional relationship with the azobenzene mole ratio within the azo-LCP. We confirmed that this tendency is caused by the change in the polymeric constraint with the temperature and the low light propagation in azo-LCP.

The strain generated by photoresponsive polymer actuators under external applied loads is a key performance parameter. Herein, we investigated the photogenerated strain under uniaxial loads in densely crosslinked azobenzene-incorporated liquid crystalline polymer (azo-LCP) actuators. Spectral analysis indicated that the liquid crystalline (LC) moieties and incorporated azobenzene moieties behave independently under load. The degree of LC mesogen distortions decreased as the applied load increased, whereas azobenzene isomerization showed high tolerance towards the external load. Such stress-response differences led to universal “two-stage” photogenerated strain behavior, with rapid decreases under low applied loads and steady linear decreases under relatively high loads. More importantly, we found that light intensity has little influence on important parameters such as the loading stage and actuator failure stress. However, these properties could be optimized by changing the crosslinking density (either azobenzene or side-chain LC concentration) in the polymeric network.

Thermoacoustic imaging (TAI) has many promising applications in biomedical imaging. Compressive sensing (CS) based TAI is able to greatly improve the time efficiency of potential realistic applications of this technique. However, the CS based TAI method, referred to as CS-TAI, is grounded on the assumption of uniform acoustic speed in the entire background, which is sometimes not the case in real applications. Acoustic heterogeneity may cause some errors in the reconstructed images. This work investigates the effect of acoustic heterogeneity for the CS-TAI modality by simulation work. It is found that bigger acoustic heterogeneities incur higher distortions in the reconstructed images. But the CS method still yields better imaging quality than the traditional back-projection algorithm when acoustic heterogeneity presents.

Microwave-induced thermoacoustic imaging (MITAI) has witnessed tremendous development in the past three decades and numerous related applications have been explored. Compressive sensing (CS) based MITAI is a newly emerging modality that can greatly reduce the number of measurements for obtaining acceptable imaging quality. This work investigates spatial resolution of CS based MITAI by using realistic frequency response of two transducers. Simulation results show that a transducer working at a higher frequency is able to image an object with smaller features. This finding agrees with the established theory of MITAI. This work is useful for potential applications and further improvement of the CS based MITAI technique.

Thermoacoustic imaging (TAI) is a promising hybrid technique for many applications. Compressive sensing (CS) based TAI is able to greatly reduce the required number of measurements to obtain a good image. This work explores the ability of CS based TAI by investigating a large sample with complicated structure details. Simulation results show that only 30 measurements are sufficient to recover most of the fine details in the sample, which is a way better than a conventional imaging method. This work is meaningful for further application of the CS based TAI in more advanced scenarios.

Bio-inspired non-precious-metal catalysts based on iron and cobalt porphyrins are promising alternatives to replace costly platinum-based catalysts for oxygen reduction reaction (ORR) in fuel cells. However, the exact nature of the active sites is still not clearly understood, and further optimization design is needed for practical applications. Here, we report a rational catalyst design process by combining density functional theory (DFT) calculations and experimental validations. Two sets of square-planar (MNxC4−x) and square-pyramid (MNxC5−x) active centers (M=Mn, Fe, Co, Ni) incorporated in graphene were examined using DFT. Fe-N5 and Co-N4 sites were identified theoretically to have the best performance in fuel cells, while Ni-NxC4−x sites catalyze the most H2O2 byproduct. Graphene samples with well-dispersed incorporations of metals were synthesized, and the following electrochemical measurements show an excellent agreement with the theoretical predictions, indicating that a successful design framework and systematic understanding toward the catalytic nature of these materials are established.

The photomechanical behavior of azobenzene-functionalized liquid-crystalline polymers (azo-LCPs) is closely related to UV light propagation. Here, we report the effect of light absorption by the LC host and the concerted isomerism of azobenzene on this property. In situ measurements of light absorptivity and computer simulations revealed that the light propagation of a liquid-crystalline polymer is affected by the UV absorption of the LC host under the same concerted isomerism of azobenzene. The lower UV light absorption of the LC host results in deeper UV light propagation and a sharper isomerization profile, which eventually induces faster bending when compared to the higher UV light absorption of the LC host. On the other hand, increasing the azobenzene concentration in the polymer greatly decreases the speed of light propagation, which is regarded as one of the factors inhibiting further increases in the bending speed of azo-LCP films.

Designing metal-oxides consisting of earth-abundant elements has been a crucial issue to replace precious metal catalysts. To achieve efficient screening of metal-oxide catalysts via bulk descriptors rather than surface descriptors, we investigated the relationship between the electronic structure of bulk and that of the surface for lanthanum-based perovskite oxides, LaMO 3 (M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu). Through density functional theory calculations, we examined the d-band occupancy of the bulk and surface transition-metal atoms ( n Bulk and n Surf ) and the adsorption energy of an oxygen atom ( E ads ) on (001), (110), and (111) surfaces. For the (001) surface, we observed strong correlation between the n Bulk and n Surf with an R -squared value over 94%, and the result was interpreted in terms of ligand field splitting and antibonding/bonding level splitting. Moreover, the E ads on the surfaces was highly correlated with the n Bulk with an R -squared value of more than 94%, and different surface relaxations could be explained by the bulk electronic structure (e.g., LaMnO 3 vs. LaTiO 3 ). These results suggest that a bulk-derived descriptor such as n Bulk can be used to screen metal-oxide catalysts.

Azobenzene liquid-crystal networks (LCNs) are well known for their photo-deformation, shrinking in UV light, and reverting to their original shape in visible light. Such reversible deformation is due to trans-cis photoisomerization of the azobenzene monomer, which disturbs well-aligned order of nematic LCN. In order to predict the photo-strain of azobenzene LCNs in multiple conditions (light intensity, polarization angle, and temperature), we propose using a density functional theory (DFT)-based modeling approach, which integrates stimulated Raman adiabatic passage calculations (STIRAP), non-linear Beer's law, and polymer physics. The model predicts that as the azobenzene ratio increases, the penetration depth of photo strain decreases, whereas the shrinkage ratio of the LCN in the unit cell increases. We identify that this opposite tendency of change is the reason why there is bending limit during the photo bending of azobenzene LCN films when increasing the ratio of the azobenzene monomer, which was also measured in experimental data.

The cis profile of azobenzene is a key factor in predicting the photodeformation of the nematic azobenzene liquid crystal network (LCN). An ab initio based method for predicting the photoisomerization profile of azobenzene is developed by coupling the stimulated Raman adiabatic passage (STIRAP) method with non-linear Beers law, and compared with experimental data. Using this combined method, we calculate the photoisomerization profile of azobenzene with various light input conditions. We identify the cis profile of the nematic LCN structure evolves into a step-like decaying shape when the direction of polarized light is parallel to the nematic direction.

Li–O2 batteries provide high-capacity energy storage, but for aprotic Li–O2 batteries, it is reported that the charge–discharge efficiency is ultimately limited by the crystal growth of insoluble Li2O2 on the porous cathode. Catalysts have been reported to improve the nucleation and morphology of Li2O2, which helps achieve high energy densities. We provide a new insight into the catalytic mechanism of the oxygen reduction reaction (ORR) in aprotic Li–O2 batteries—the oxygen sites on the surface play a more important role than the exposed metal sites—via a study based on the density functional theory (DFT) examining α-MnO2 surfaces. Lithium ions from electrolytes are found to interact with the surface oxygen sites and form surface lithium sites, facilitating further growth of Li2O2. A larger number of initial growth points with uniform distribution makes Li2O2 well dispersed, forming small particles, which benefit both the ORR and oxygen evolution reactions (OER). This design concept for oxygen sites has b...

NiO/ γ -Al 2 O 3 catalysts with NiO content of 9 wt% and 24 wt% were prepared by solid state reaction method. They are annealed in air at temperatures from 100 °C to 1000 °C. Positron lifetime spectra were measured to study the microstructure variation during annealing process. Four positron lifetime components were resolved with two long lifetime τ 3 and τ 4 , which can be attributed to the ortho-positronium lifetime in microvoids and large pores, respectively. It was found that the longest lifetime τ 4 is rather sensitive to the chemical environment of the large pores. The NiO active centers in the catalysts cause decrease of both τ 4 and its intensity I 4 , which is due to the spin-conversion of positronium induced by NiO. However, after heating the catalysts above 600 °C, abnormal increase of the lifetime τ 4 is observed. This is due to the formation of NiAl 2 O 4 spinel from the reaction of NiO and γ -Al 2 O 3 . The generated NiAl 2 O 4 weakens the spin-conversion effect of positronium, thus leads to the increase of o-Ps lifetime τ 4 . Formation of NiAl 2 O 4 is further confirmed by both X-ray diffraction and X-ray photoelectron spectroscopy measurements.

Understanding and effectively predicting the thermal stability of ternary transition metal oxides with heavy elements using first principle simulations are vital for understanding performance of advanced materials. In this work, we have investigated the thermal stability of mullite RMn2O5 (R = Bi, Pr, Sm, or Gd) structures by constructing temperature phase diagrams using an efficient mixed generalized gradient approximation (GGA) and the GGA + U method. Simulation predicted stability regions without corrections on heavy elements show a 4-200 K underestimation compared to our experimental results. We have found the number of d/f electrons in the heavy elements shows a linear relationship with the prediction deviation. Further correction on the strongly correlated electrons in heavy elements could significantly reduce the prediction deviations. Our corrected simulation results demonstrate that further correction of R-site elements in RMn2O5 could effectively reduce the underestimation of the density functional theory-predicted decomposition temperature to within 30 K. Therefore, it could produce an accurate thermal stability prediction for complex ternary transition metal oxide compounds with heavy elements.

This study introduces a facile and novel route to synthesize the N + Ni codoped anatase TiO2 nanocrystals with exposed {001} facets through two-step hydrothermal reaction. The microstructures, chemical compositions, and photocatalytic properties of the codoped TiO2 were characterized using X-ray diffractometer, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis spectrometry, and photoluminescence emission spectra. The experimental results revealed that (i) the elements N and Ni have been successfully codoped into the anatase TiO2 with exposed {001} facets; (ii) the size of the TiO2 reached to a narrow range of 5–15 nm; (iii) the codoped TiO2 exhibited an additional visible light absorption band from 400 to 500 nm, which greatly improved the photocatalytic activity. The theoretical calculations for band structure and total energy also provided a good explanation for the experimental results.

Herein, a facile strategy for the controllable synthesis of BiVO4@C core-shell nanoparticles on reduced graphene oxide (RGO) is reported. The BiVO4 particle size can be controlled in the process by adjusting the volume ratio of glycerol in the sol-gel solution. The glycerol layers adsorbed on BiVO4 (BiVO4@glycerol) made it possible to form hydrogen bonds between BiVO4@glycerol and graphene oxide with the assistance of ultrasound. After thermal treatment, glycerol adsorbed on the BiVO4 particles formed amorphous carbon shells to link the particles and RGO. As a result, the obtained RGO-BiVO4@C nanocomposite showed a five times higher rate in O2 evolution from water under visible-light irradiation. Also, it demonstrated a six times higher photocatalytic performance enhancement than that of pure BiVO4 in the degradation of Rhodamine B. The enhanced performance is attributed to the carbon shells that restrict the growth of BiVO4 , the reduced graphene oxide that improves the electronic conductivity of the composite, and importantly, the bonds formed between the carbon shells and RGO that reduce the recombination loss of photogenerated charges effectively. The strategy is simple, effective, and can be extended to other ternary oxides with controlled size and high performance.

The beam steering mechanism has been a key element for various applications ranging from sensing and imaging to solar tracking systems. However, conventional beam steering systems are bulky and complex and present significant challenges for scaling up. This work introduces the use of soft deployable reflectors combining a soft deployable structure with simple kirigami/origami reflective films. This structure can be used as a macroscale beam steering mechanism that is both simple and compact. This work first develops a soft deployable structure that is easily scalable by patterning of soft linear actuators. This soft deployable structure is capable of increasing its height several folds by expanding in a continuous and controllable manner, which can be used as a frame to deform the linearly stretchable kirigami/origami structures integrated into the structure. Experiments on the reflective capability of the reflectors are conducted and show a good fit to the modeling results. The proposed principles for deployment and for beam steering can be used to realize novel active beam steering devices, highlighting the use of soft robotic principles to produce scalable morphing structures.

Understanding and effectively predicting the thermal stability of ternary transition metal oxides with heavy elements using first principle simulations are vital for understanding performance of advanced materials. In this work, we have investigated the thermal stability of mullite RMn2O5 (R = Bi, Pr, Sm, or Gd) structures by constructing temperature phase diagrams using an efficient mixed generalized gradient approximation (GGA) and the GGA + U method. Simulation predicted stability regions without corrections on heavy elements show a 4-200 K underestimation compared to our experimental results. We have found the number of d/f electrons in the heavy elements shows a linear relationship with the prediction deviation. Further correction on the strongly correlated electrons in heavy elements could significantly reduce the prediction deviations. Our corrected simulation results demonstrate that further correction of R-site elements in RMn2O5 could effectively reduce the underestimation of the density functional theory-predicted decomposition temperature to within 30 K. Therefore, it could produce an accurate thermal stability prediction for complex ternary transition metal oxide compounds with heavy elements.