Synchrotron XRD Research Articles

The Complex and Spatially Heterogeneous Nature of Degradation in Heavily Cycled Li-ion Cells

As service lifetimes of electric vehicle (EV) and grid storage batteries continually improve, it has become increasingly important to understand how cells perform after extensive cycling. The multifaceted nature of degradation in Li-ion cells can lead to complex behavior that may be difficult for battery management systems or operators to model. Accurate characterization of heavily cycled cells is critical for developing accurate models, especially for cycle-intensive applications like second-life grid storage or vehicle-to-grid charging. In this study, we use operando synchrotron x-ray diffraction (SR-XRD) to characterize a commercially manufactured polycrystalline NMC622 pouch cell that was cycled for more than 2.5 years. Using spatially resolved synchrotron XRD, the complex kinetics and spatially heterogeneous behavior of such cells are mapped and characterized under both near-equilibrium and non-equilibrium conditions. The resulting data is complex and multifaceted, requiring a different approach to analysis and modelling than what has been used in the literature. To show how material selection can impact the extent of degradation, we compare the results from polycrystalline NMC622 cells to an extensively cycled single-crystal NMC532 cell with over 20,000 cycles—equivalent to a total EV traveled distance of approximately 8 million km (5 million miles) over six years.

Grain size dependent deformation microstructure evolution and work-hardening in CoCrNi medium entropy alloy

This study clarified the grain size dependence of the deformation microstructure evolution and work-hardening behavior in CoCrNi medium entropy alloy. We fabricated fully recrystallized specimens with coarse-grained (CG) and ultrafine-grained (UFG) specimens by severe plastic deformation and subsequent annealing processes. Tensile deformation was applied to the specimens at room temperature. The UFG specimen exhibited both high strength and high ductility compared to conventional UFG metals due to the high work-hardening ability. In the CG specimen, three distinct types of deformation microstructures consisting of dislocations and deformation twins developed depending on grain orientations, similar to the single-crystalline specimens. In the UFG specimen, widely extended stacking faults and randomly-tangled dislocations were found to coexist in most grains. Deformation twins were found to nucleate without evidence of dislocation reactions regardless of grain orientations, implying abnormal nucleation mechanisms of deformation twins in the UFG specimen. Dislocation densities quantified by in-situ synchrotron XRD measurements during tensile deformation were higher in the UFG specimen than those in the CG specimen and conventional UFG metals. Our analysis showed that the work-hardening behavior of the specimens was primarily controlled by increases in dislocation density as well as the introduction of planar defects during deformation. Through comparisons with the CG specimen and conventional UFG metals, we concluded that the excellent work-hardening ability of the UFG specimen was mainly due to the evolution of unique deformation microstructures and rapid increase in dislocation density, which could be due to inhibited dynamic recovery in the MEA.

Elucidating the Dynamics of Biodegradation and Biosynthesis of Magnetic Nanoparticles in Human Stem Cells.

Iron oxide nanoparticles, due to their magnetic properties, are versatile tools for biomedical applications serving both diagnostic and therapeutic roles. Their performance is intricately intertwined with their fate in the demanding biological environment. Once inside cells, these nanoparticles can be degraded, implying a loss of magnetic efficacy, but also transformed into neo-synthesized magnetic nanoparticles, potentially restoring functionality. This study aims to delineate biological features governing these processes. Magnetic nanoparticles are internalized in human mesenchymal stem cells (hMSCs), and their biotransformations are investigated from nano- to micro-scale using electron microscopy (STEM-HAADF, HRTEM, SAED), a benchtop magnetic sensor, and fine structural characterizations (synchrotron XRD, VSM). Results evidence a delicate equilibrium between the biodegradation and biosynthesis of magnetic nanoparticles, with biotransformation kinetics depending on cell density at magnetic labeling and on spatial cell configuration (monolayers vs spheroids). The biotransformed nanoparticles, composed of magnetite or maghemite, are localized within endosomal/lysosomal compartments and associated with the recruitment of ferritin proteins.

Li2FeCl4 as a Cost-Effective and Durable Cathode for Solid-State Li-Ion Batteries.

Low-cost cathode materials with high energy density and good rate performance are critical for the development of next-generation solid-state Li-ion batteries (SSLIBs). Here, we report Li2FeCl4 as a cathode material for SSLIBs with highly reversible Li intercalation and deintercalation, a high operation voltage of 3.7 V vs Li+/Li, good rate capability, and good cycling stability with an 86% capacity retention after 6000 cycles. Operando synchrotron XRD reveals that the phase evolution of Li2FeCl4 during charge-discharge cycling involves both solid-solution and two-phase reactions, which maintains a very stable framework during Li insertion and extraction.

High-pressure synthesis, crystal structure and anisotropic thermal/compressive behaviors of pseudo-ternary (V,Cr,Mo)P4

Pseudo-ternary CrP4-type (V,Cr,Mo)P4 was successfully synthesized at the conditions of 4 GPa and 900 °C by using a large volume multi-anvil-type press. SEM-EDS and STEM analyses revealed that the synthesized pseudo-ternary (V,Cr,Mo)P4 contains almost equimolar amounts of transition metals. The lattice parameters and unit cell volume of (V,Cr,Mo)P4 yield the average value of its end-members. The low-temperature (133 K–333 K) in-situ synchrotron XRD measurements demonstrated that the c-axis showed the highest coefficient of thermal expansion, followed by the b-axis and the a-axis. These thermal behaviors are the same as the binary end-members and pseudo-binary (V,Cr)P4. While from the high-pressure (P < 10 GPa) in-situ synchrotron XRD measurements, it was found that (V,Cr,Mo)P4 showed no phase transition and compression behaviors in which the c-axis was more compressible than the other two axes (b and a) and the b-axis was slightly compressible more than the a-axis. The zero-pressure bulk modulus of 106 (1) GPa and 122.1 (7) GPa were obtained for (V,Cr)P4 and (V,Cr,Mo)P4, respectively. MoP6 octahedral is highly distorted in comparison with VP4 and CrP4, thus the incorporation of MoP4 greatly yields incompressible behaviors of CrP4-type phosphides with respect to temperature and pressure.

Pressure-induced abnormal blue-shift emission enhancement and phase transition of perovskite DMAPbI3

Designing low-dimensional hybrid organic–inorganic perovskites (HOIPs) with enhanced broadband emission under ambient conditions remains a pressing challenge. Here, interesting results of emission blueshift and enhancement were successfully achieved by pressure modulation of the (NH2(CH3)2PbI3 ((NH2(CH3)2 = DMA) structure. The observed rapid blueshifted emission is closely related to the distortion of PbI6 octahedron induced by phase transition from the P63/mc phase to the P1 phase at 0.8 GPa, which has been confirmed by in situ high-pressure PL, UV–vis absorption, synchrotron XRD and Raman spectroscopy. The pressure-induced PL enhancement of DMAPbI3 can be ascribed to the mechanism that the distorted PbI6 octahedrons promote the radiative recombination of self-trapped excitons by increasing the activation barrier energy for detrapping. The PL intensity enhancement was retained at 4 times the initial value after the pressure was released. These findings deepen the understanding of the structure-property relationships of one-dimensional perovskite and reveal the roles of pressure in regulating the optical properties of perovskites.

Investigation of 40 Ah Prismatic Batteries Operating Under Fast-Charge Conditions Using Operando Synchrotron XRD Technique

The pressing challenges posed by the energy crisis and the impact of climate change have forced a gradual replacement of traditional internal combustion engine (ICE) automobile powertrains with electrochemical energy storage devices. However, a boost of the electric vehicles (EVs) market, by significant battery performance enhancements are consistently required, primarily due to numerous persistent concerns. One of the key features targeted by battery and EVs industries is the rapid charging capability, making EVs more competitive with the quick refueling of traditional gasoline vehicles. Notably, despite the clear benefits of fast charging technology, the accelerated battery degradation after fast and extreme fast charging raises on top of the drawbacks of this technology. Therefore, understanding of heterogeneity and structural transformations within battery systems is of high interest.In this regard, we attempt to investigate the structural properties of a LiNi1/3Mn1/3Co1/3O2 (NMC111) /graphite fresh industrial prismatic cell using synchrotron XRD under fast charge conditions. The investigated battery is a PHEV cell with an experimental capacity of 40 Ah. It was taken from a range rover vehicle pack after being disassembled. The evolution of the composite anode and cathode structures was followed by operando wide-angle X-ray scattering (WAXS). Using this approach, we were able to measure and quantify the different phases of graphite and NMC111 lithiation/delithiation at various potentials by analyzing the corresponding Bragg peaks. By that, we were able to detect some heterogeneities in the degree of lithiation/delithiation within the cell upon charge. In addition, a comparison between a fresh cell and another aged cell, with a state of health (SOH) of 88%, was made in order to investigate the effect of aging under fast charging conditions on the performance of the industrial LIBs.

(Invited) Carbon Phase Adjustment by Multi-Configuration Ligand in Endohedral Metallofullerene Derivatives Gd@C82(morpholine)7 Under High Pressure

Metallofullerenes present an ideal research object for developing new carbon structures with improved properties under high pressure. In this presentation, high pressure investigation is realized on metallofullerene derivatives (Gd@C82(morpholine)7) by applying in situ synchrotron XRD, Raman, and IR spectroscopy, combined with high pressure density functional theory (DFT) calculations. The regulations of multi-configuration morpholine ligands avoid the direct collapse of the carbon cages commonly happened to fullerenes, making the fine structure transformation possible for the first time, including ligand configuration exchange, anisotropic shrinkage of cage, new constructed bonds, and even the encaged metal’s movement with increasing pressure. The charge-transfer principle as the beneath driving force of structural transition is found. These findings demonstrate that multi-configuration ligand maps an innovative strategy for phase transition control of metallofullerenes under high pressure, thus providing deep insight, step by step, into the phase transition mechanism of these hybrid molecular systems on molecular level.

High-throughput strategy to design high entropy alloys with an FCC matrix, L12 precipitates, and optimized yield stress

This work proposes a methodology for designing high-strength precipitation-hardened high entropy alloys (HEAs) with an FCC matrix and L12 precipitates. High-throughput solidification calculations were conducted using the CALPHAD method, evaluating 11,235 alloys in the Cr-Co-Ni-Al-Ti system under specific boundary conditions. The acquired information was used to filter the alloys, focusing on alloys exhibiting an FCC+L12 phase field at 750 °C, a solidification interval narrower than 100 °C, and a solvus temperature under 1100 °C. The filtered alloys were analyzed to estimate their solid solution and precipitation hardening contributions to yield strength, with antiphase boundary energy (APB) assessed using two models. Three alloys were selected for testing the proposed strategy, including one with the highest yield stress and others for comparison. These alloys were produced, processed, and characterized using DSC, synchrotron XRD, SEM, and TEM. The results showed that the desired microstructure was achieved, with the alloys consisting of an FCC matrix and a high-volume fraction of L12 precipitates. Tensile tests at room temperature, 650 °C, 750 °C, and 850 °C demonstrated that the proposed model predicts well the yield strength trends, demonstrating the potential of the proposed approach for accelerating the discovery and development of novel HEAs with tailored properties.

Magnetization dynamics and domain reversal in electrodeposited permalloy thin films: impact of thickness and annealing treatment

The domain reversal and magnetization dynamics of electrodeposited permalloy (Fe20Ni80) thin films on conducting ITO/glass substrate was investigated using Magneto-optic Kerr effect microscopy and ferromagnetic resonance. Permalloy thin films were electrodeposited with thickness ranging from 66 nm to 330 nm. Synchrotron XRD confirmed the deposited permalloy in FCC phase without any impurity. The squared hysteresis with very low coercivity (Hc ∼ 5 Oe) established soft magnetic nature of the films. Further, angular MOKE hysteresis measurements with simultaneous domain imaging revealed four-fold surface anisotropy in as-deposited film ensuing magnetization reversal via branched and ripple domains. The annealing treatment in Ar+H2 atmosphere removed surface anisotropy and renovated the magnetization reversal through 180° branched domains with rapid magnetization switching. Ferromagnetic resonance spectroscopy discloses reduction in the gyromagnetic ratio (γ) as well as in Gilbert damping parameter (α) as the film thickness increases. The lowest Gilbert damping for 330 nm film measured at 0.022, which further reduced to 0.018 after annealing. The combination of rapid magnetization switching and low Gilbert damping in the electrodeposited permalloy thin films render them promising for implementation in high-frequency microwave devices devices and magnetic sensors.

Mechanism of DSA effect correlating to the macroscopic PLC banding in high-Mn austenitic steel

Mechanism of dynamic strain aging (DSA) effect in high-Mn austenitic steel, and its correlation with the Portevin-Le Chatelier (PLC) banding, was elucidated using the in-situ synchrotron XRD measurement and digital image correlation (DIC) method during tensile test. The average dislocation velocity beyond the PLC band ranged from 10−2 to 10−1 nm/s, while reached to the order of 10° nm/s within the PLC band. In comparison, carbon diffusivity was significantly lower, allowing carbon atoms to diffuse only from 10−7 to10−9 nm in one second. The findings indicate that dislocations beyond the advancing PLC band were pinned by nearby carbon atoms, while dislocations within the PLC band became de-pinned from the carbons. Such localized pinning and de-pinning of dislocations occurred sequentially during deformation, appearing as the propagation of PLC bands in macroscopic scale.

Rational design of an optimal Al-substituted layered oxide cathode for Na-ion batteries

Layered oxide cathodes, a promising avenue for Na-ion batteries, hold the highest potential for commercialization. Herein, we delve into the structural and electrochemical properties of Al-substituted layered oxides in our quest to pinpoint the optimal cathode composition in the Na3/4(Mn-Al-Ni)O2 pseudo-ternary system. The cathode materials investigated were synthesized in three distinct phase configurations, which include two monophasic configurations with P3 and P2-type structures and a third biphasic cathode with equal proportions of P3 and P2 phases. The fractions of the P3 and P2 type phases in the cathode materials were manipulated by adjusting the calcination temperature. The varying concentration of Mn3+ and Mn4+, confirmed by X-ray photoelectron spectroscopy, was found to impact the cyclic stability of these materials significantly. During electrochemical testing, the P3 cathodes showed impressive rate performance and exhibited an excellent specific capacity of 195 mAh g−1 at 0.1C. Regarding cyclic performance, the biphasic cathodes consistently outperformed their monophasic counterparts, with P3/P2-Na0.75Mn0.50Ni0.25Al0.25O2 exhibiting 82 % capacity retention after 300 cycles. Analysis of operando Synchrotron XRD data revealed an absence of P3 to O3 type phase transition in the cathodes even at low voltages where large structural variations to the unit cell structure were observed. The absence of P3 to O3 transformations and the superior electrochemical performance of Na0.75Mn0.50Ni0.25Al0.25O2 underlines the importance of Al substitution and P3/P2 biphasic structure in enhancing the electrochemical performance of layered oxides.

Temperature-dependent synchrotron XRD study and electrical properties of the (1-x)BZT-(x)BCT lead-free piezoceramics

In recent years, researchers have shown the feasibility of the BZT-xBCT lead-free piezoelectric ceramics for using in various applications such as actuator, energy harvester, high-frequency ultrasonic transducer, etc. However, little evidence of temperature-dependent electrical properties of the BZT-xBCT ceramic was found. Moreover, some researchers have utilized Raman spectroscopy to observe the phase transition of the BZT-xBCT ceramic, but the Raman spectra of ferroelectric polymorphic phases are almost identical and hard to distinguish. In contrast, synchrotron radiation exhibits a high degree of monochromatization and collimation with smaller wavelength than x-ray tubes, resulting in the improvement of resolution for identifying the overlapping peaks. Therefore, this work aims to determine phase coexistence of the BZT-xBCT ceramic near phase boundary region by using high-resolution synchrotron x-ray powder diffraction in comparison with the temperature-dependent electrical properties. This work found that the occurrence of thermally-induced polymorphic phase transformations for the BZT-xBCT ceramics plays a significant role in the observed temperature-dependent electrical properties. Moreover, this work observed a trace of surface damaged layer (the presence of low-angle shoulder in the synchrotron XRD profiles) from mechanical grinding during sample preparation for XRD measurement, which has not previously been found in the BZT-xBCT ceramics. These finding will help to better understand the temperature-dependent functional properties of the BZT-xBCT ceramic for transferring into practical applications.

Synchrotron diffraction residual stresses studies of electron beam welded high strength structural steels

In recent years, there's been a strong focus on enhancing high-strength structural steels (HSSSs), making them tougher, stronger, lighter, and more weldable. However, these steels face challenges like cold cracking sensitivity (CCS) and reduced toughness with higher heat input. Therefore, exploring HSSSs with advanced welding techniques like electron beam welding (EBW) is crucial. EBW known for its innovation and precision, is gaining popularity in HSSSs applications for vehicles, construction industries etc. offering advantages like narrow welds, reduced heat-affected zone (HAZ) and low distortion. It is essential to understand the influence of residual stresses (RS) in HSSSs which ultimately affect structural integrity and fatigue life. Using EBW on HSSSs, coupled with synchrotron XRD for residual stress studies, has great potential to advance this research significantly. In this work, a 15-mm-thick EB-welded joint of S960QL and S960 M steels was used to study the RS. At an energy level of 20 keV, RS data from the synchrotron XRD method and its result on the top of welded joints for both types of steel were compared. S960 M steel showed a longitudinal tensile stress of 250 MPa at the weld toe, approximately 1.8 times higher than the 138 MPa observed in S960QL steel under similar conditions. In transverse stress, S960QL exhibits a higher stress of 279 MPa compared to S960 M 46 MPa at the weld toe, approximately 83% lower. The synchrotron method measured 76% lower LRS for S960QL compared to conventional XRD, while S960 M exhibited 55% lower LRS using the same approach.

Identification of optimal composition with superior electrochemical properties along the zero Mn3+ line in Na0.75(Mn-Al-Ni)O2 pseudo ternary system

Biphasic layered oxide cathodes, known for their superior electrochemical performance, are prime candidates for commercializing in Na-ion batteries. Herein, we unveil a series of P3/P2 monophasic and biphasic Al-substituted Na34Mn5-x8Al2x8Ni3-x8O2 layered oxide cathodes that lie along the ‘zero Mn3+ line’ in the Na3/4(Mn-Al-Ni)O2 pseudo-ternary system. The structural analysis showed a larger Na+ conduction bottleneck area in both P3 and P2 structures with a higher Al3+ content, which enhanced their rate performance. In each composition, the P3/P2 biphasic compound with nearly equal fractions of P3 and P2 phases outperformed their monophasic counterparts in almost all electrochemical performance parameters. Operando synchrotron XRD measurements obtained for the monophasic P3 and biphasic P2/P3 samples revealed the absence of the O3 phase during cycling. The high structure stability and faster Na+ transport kinetics in the biphasic samples underpins the enhancement of electrochemical properties in the Al-substituted P3/P2 cathodes. These results highlight fixed oxidation state lines as a novel tool to identify and design layered oxide cathodes for Na-ion batteries in pseudo-ternary diagrams involving Jahn-Teller active cations.

Development of the first “encapsulated oleogel-in-oleogel” system with tailorable lipid digestion

Despite containing a higher proportion of unsaturated fatty acids than traditional solid and semi-solid fats, the calorie-dense nature of oleogels presents a challenge when incorporating them into foods. The next generation of oleogels should feature a customizable lipid digestion profile while having minimal impact on other properties of the food products. To achieve this goal, we developed the first-of-its-kind “encapsulated oleogel-in-oleogel” system with tailorable digestibility. To obtain such a system, a Pickering emulsion containing wax-based oleogel stabilized using crystalline nanocellulose was spray dried using a soluble dietary fibre as wall material (the inner oleogel). Following, the resulting encapsulated oleogel was added to a molten monoglyceride-based oleogel and cooled to set the outer oleogel. The morphological properties of the encapsulated oleogel-in-oleogel system were studied by cryo- and FE-SEM and polarized and fluorescence microscopy. The results of DSC and synchrotron XRD showed that waxes crystallized inside the inner oleogel droplets, confirming also that the entire preparation of the encapsulated oleogel-in-oleogel system did not alter the nanostructure of waxes and monoglyceride crystals. The results of in vitro digestion revealed that both Pickering emulsion and the resulting spray dried encapsulated oleogel were partially indigestible, leading to a lower and tailorable lipid digestion in the encapsulated oleogel-in-oleogel system compared to that of the oil and conventional oleogels. We demonstrated that the digestibility of the encapsulated oleogel-in-oleogel system can be conveniently modulated by varying the ratio between the encapsulated oleogel and outer oleogel, showing promise for developing a new generation of oleogels with tailored digestibility, lower calories, and high dietary fibre content.

High-pressure study of synthesized α-Bi2O3/NiBi3 nanostructured composite: In-situ synchrotron XRD measurements, DFT calculations and PDF approach

We investigated a nanostructured composite of α-Bi2O3/NiBi3, which was synthesized through high-energy milling, under high-pressure conditions of up to 30 GPa. To track its structural changes, we employed in-situ synchrotron angle-dispersive X-ray diffraction measurements in conjunction with density functional theory calculations. Crystallographic information was derived using the Rietveld method and DFT computations. Additionally, we examined the chemical short-range order using pair distribution functions and determined the compressibility parameters through the Birch-Murnaghan equation of state.We explored the high-pressure behavior of a nanostructured composite of α-Bi2O3/NiBi3, applying pressures up to 30 GPa. The composite sample, synthesized by mechanical alloying, underwent thorough structural characterization by X-ray diffraction, high-resolution transmission electron microscopy and Raman spectroscopy. The sample's response to applied pressure was studied by analyzing crystallographic data obtained from in-situ synchrotron angle-dispersive X-ray diffraction measurements and density functional theory calculations. Crystallographic information from experiments was refined using the Rietveld method. Additionally, chemical short-range order was examined using pair distribution functions, and compressibility parameters were determined via the Birch-Murnaghan equation of state. This investigation into the high-pressure behavior of NiBi3 provides valuable insights for future studies and potential applications of similar materials in extreme pressure environments.

Tailoring microstructure and mechanical properties of an LPBF-processed beta Ti-Nb alloy through post-heat treatments

This study provides a comprehensive analysis of a Ti‑42Nb alloy produced via laser powder bed fusion (LPBF) with varying post-heat treatment durations within the α + β phase range at 723 K. Synchrotron XRD analysis revealed the formation of the metastable orthorhombic αiso'' phase during heat treatment, acting as an intermediate to the stable α phase. With prolonged heat treatment, the αiso'' phase fraction increased, reaching approximately 25 % after 108.0 ks. SEM analysis identified β grain boundaries as primary sites for early αiso'' precipitation, while intragranular αiso'' precipitation was delayed. Up to 28.8 ks, volume fraction and size of intragranular precipitates exhibited notable variations due to minor Nb content fluctuations from LPBF processing, resulting in an increased spread of hardness and Young's modulus on the micro scale. Tensile tests revealed significant strength enhancement through post-heat treatment for 108 ks compared to the as-built state, achieving a yield strength of around 1060 MPa (50 % increase) and ultimate tensile strength of 1125 MPa (55 % increase). Extended growth of the αiso'' phase led to an increased Young's modulus, reaching 87 GPa after 108.0 ks. These findings provide valuable insights for developing post-heat treatment strategies for LPBF-produced Ti‑42Nb implants, including both bulk materials and lattice structures.

Similarities and differences among selected gemmological varieties of chalcedony: chemistry, mineralogy and microstructure

AbstractThis study describes a new variety of chalcedony with a unique inhomogeneous bluish green hue, named aquaprase. It was discovered in Africa and is considered to be a valuable addition to the gem trade. A multi-methodological approach was used to examine its chemistry, mineralogy and microstructure, which were then compared to those of chrysoprase and agate, two of the most popular varieties of chalcedony. Optical microscopy revealed a complex microstructural heterogeneity in the different colour intensity areas/bands of aquaprase and agate, whereas chrysoprase exhibited a more homogeneous coexistence of micro- and cryptocrystalline quartz. High-resolution synchrotron XRD was essential for highlighting the complex assemblage of various types of α-quartz in aquaprase and agate (which differ in terms of crystal size and/or cell parameters). Micro-Raman spectroscopy revealed α-quartz and moganite in all three varieties of chalcedony and the presence of the nickel-bearing layered silicate mineral, willemseite, in chrysoprase, which is responsible for its green colouration. The chemical analysis displayed a homogeneous composition of agate, as well as high levels of nickel content in the chrysoprase variety. Aquaprase showed significant amounts (ppm by weight) of trace elements (Al, Mg, Na, K, Ca, Ti, U and Fe) characteristic of its formation environment, as well as high values of Cr, which are thought to be the cause of its bluish green colouration.

Investigating the thermal stability of compressive residual stress in a gradient nanostructured austenitic stainless steel by in-situ XRD and TEM

A widely used approach for extending the fatigue life of engineering steels is through the introduction of compressive residual stress (CRS). The thermal stabilities of the introduced residual stress may determine their effectiveness in high-temperature application, which had been extensively studied by ex-situ technology in the past two decades. Here, the in-situ heating techniques of synchrotron XRD, XRD and TEM were used to study the evolution of CRS and corresponding microstructural evolution in a gradient nanostructured (GNS) austenitic stainless steel. As the temperature increased upto 500 °C, the magnitude of CRS decreased continuously by 63% when the phase composed of 100% strain-induced α'-martensite in the GNS layer, while it was decreased by 23% in the dual-phases composed of 60% α' and 40% γ. This result was attributed to the fact that the CRS introduced by the α'-martensite belongs to the type III micro-stress and was stored in the dislocations, which shows a high recovery trend upon heating. However, the CRS in the dual-phase structures is the type II intergranular stress, which is relatively stable upon heating. The current work suggested the importance of α'-martensite on the stabilizing of CRS, which may guide the materials design for high-temperature application.