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My comments concern the significant errors in the crystallographic part of the commented paper. The diffraction patterns are erroneously analysed and the final chemical composition is different than those supposed in the paper. There are also some manipulations with data. [ABSTRACT FROM AUTHOR]

This paper presents a holistic view of the structural phase transitions in nanocrystals. The databases for size-induced phase transitions is a main part of this paper. The database on transitions with temperature contains 603 items on 415 crystals, and database on transitions under high pressure contains 209 items in 124 crystals. Moreover, some new aspects of such transitions are presented like island diagram and new analysis of anomalous compressibility observed in some nanocrystals. [ABSTRACT FROM AUTHOR]

My comments concern some errors in the crystallographic part of the commented paper. The diffraction patterns are erroneously analysed and the final data on the structure (symmetry and unit cell parameters) are different than those supposed in the paper. [ABSTRACT FROM AUTHOR]

My comments concern the error in the lattice parameters and chemical composition of BiHoZnCeO6 perovskite published in the commented paper. The most probable composition of the studied sample is CeO2:Bi,Ho,Zn. [ABSTRACT FROM AUTHOR]

• The title paper reporting on Ba 2 BiVO 6 is commented. • Reported diffraction data are incompatible with the proposed Ba 2 BiVO 6 formula. • Ba 2 BiVO 6 is NOT a new perovskite but a dubious material. • The main part of the studied sample is Ba 3 (VO 4) 2. • The structural data are copied from another paper (plagiarism). My comments concern the errors in the crystallographic part of the title paper. The diffraction patterns are erroneously analysed and authors claim to have prepared a single phase new double perovskite Ba 2 BiVO 6. A critical review of the experimental data reveals that the diffraction patterns are questionable and do not support the proposed formula. It is clear that the studied sample contains Ba 3 (VO 4) 2 crystal as a major part constituent. Thus, the subsequent data have no scientific value. [ABSTRACT FROM AUTHOR]

The new form of the phase diagram is proposed for nanocrystals. This island diagram shows the regions of the calcination temperature required to obtain the nanocrystals of given range of crystallite size. This explains why the temperature-induced phase transitions are not possible in some crystals. However, the change of crystallite size can induce the phase transition. [ABSTRACT FROM AUTHOR]

• The commented paper has several errors. • The phase analysis is wrong. • Ba 3 Bi 2 MoO 9 does not exist. My comments concern the severe errors in the crystallographic part of the paper "Development of a novel triple perovskite barium bismuth molybdate material for thermistor-based applications" by D. Panda et al. (Mater. Sci. Engin. B 296 (2023) 116616). Authors have proposed that their sample is a derivative of two different crystals, Ba 2 Bi 2 O 5 and BaMoO 4. Unfortunately, this is not the same as a creation of a new crystal with the supposed chemical formula Ba 3 Bi 2 MoO 9. Moreover, the structure analysis is wrong what is presented by inacceptable high reliability factors. [ABSTRACT FROM AUTHOR]

My comments concern the significant errors in the crystallographic part of the commented paper. The diffraction patterns are erroneously analysed. The studied sample contain two phases what can influence on the final results of experiments. [ABSTRACT FROM AUTHOR]

• It is shown that the commented paper has severe errors. • The analysis of the diffraction pattern was made without success. • The chemical composition of the studied crystals is unknown. My comments concern the errors in the crystallographic part of the commented paper. Moreover, the true chemical composition of the studied sample is different than BaNaFeWO 6 as proposed by authors. Therefore, the subsequent data on other measurements may have no scientific value. [ABSTRACT FROM AUTHOR]

• It is shown that the commented paper has severe errors. • The analysis of the diffraction pattern was made without success. • The chemical composition of the studied crystals is unknown. My comments concern the errors in the crystallographic part of the commented paper. Moreover, the true chemical composition of the studied sample is different than BaNaFeWO 6 as proposed by authors. Therefore, the subsequent data on other measurements may have no scientific value. [ABSTRACT FROM AUTHOR]

My comments concern the errors in the crystallographic part of the commented paper. Moreover, the true chemical composition of the studied sample is different than (BaSr)FeMoO 6 as proposed by authors. Thus, the subsequent data have no scientific value, unless the chemical composition of the sample are clarified. [ABSTRACT FROM AUTHOR]

My comments concern the errors in the crystallographic part of the commented paper. The diffraction patterns are erroneously analysed. The crystal structure was not presented in the commented paper. • Correction of erroneous analysis of diffraction patterns. • Comparison of unit cells relation to the content of Ca dopant. • The crystal structure was not given in the commented paper. [ABSTRACT FROM AUTHOR]

My comments concern the severe errors in the crystallographic part of the commented paper. The correct formula is proposed to be Bi1–xYxFeO3 ('Bi0.85Y0.15FeO3') instead of BiFe0.85Y0.15O3. It is found that the studied sample is bi-phasic with nearly equal amounts of BiFeO3:Y and Bi25FeO39:Y. The actual composition of the studied crystals is not known. Moreover, the type of unit cell is not correct. [ABSTRACT FROM AUTHOR]

• Several erroneous statements were corrected. • It is shown that the presented data on atomic position are false. • There is no texture in the studied sample. My comments concern the serious errors in the crystallographic part of the commented paper. Some manipulation of data are also found. The presented comments are to allow the readers and students to understand where the errors may be made in similar papers. [ABSTRACT FROM AUTHOR]

My comments concern the severe errors in the crystallographic part of the commented paper. The correct formula is proposed to be Bi1-xGdxFeO3 instead of BiFe0.95Gd0.05O3. Thus, the actual composition of the studied crystal is not known. Furthermore, it is evident that the sample contains at least three different phases. The subsequent studies do not present the properties of the title compound. [ABSTRACT FROM AUTHOR]

I would like to comment the crystallographic part of the paper by Santosh Kumor Parida and Rama Narayan Prasad Choudhary entitled 'Preparation method and cerium dopant effects on the properties of BaMnO3 single perovskite' and published in 'Phase Transitions' in September 2020 [1]. There are several errors that should be corrected, if possible. [ABSTRACT FROM AUTHOR]

My comments concern the severe errors in the crystallographic part of the commented paper. The actual composition of the studied crystals is not known, but the diffraction patterns and Rietveld analysis suggest the chemical formula of Ba 2 Sr(VO 4)(FeO 4) instead of Ba 1.5 Sr 0.5 FeVO 6. Moreover, the symmetry should be trigonal. [ABSTRACT FROM AUTHOR]

My comments concern the significant error in the crystallographic part of the commented papers. It was discovered that the studied nanocrystals are of sillenite type and the correct formula should be Bi 25 FeO 39 :Co,Ti and Bi 25 FeO 39 :Ni,Ti instead of BiFeO 3. Moreover, the type of unit cell is not correct. Due to the doping the new type of unit cell, previously unknown, was proposed for such crystals. It was found that the studied sample contains two slightly different phases of the sillenite type. The actual chemical composition of the studied crystals is not known. [ABSTRACT FROM AUTHOR]

My comments concern the significant errors in the crystallographic part of the commented paper. [ABSTRACT FROM AUTHOR]

My comments concern the severe errors in the crystallographic part of the commented paper. The actual composition of the studied crystals is not known, but the diffraction patterns and Rietveld analysis suggest the chemical formula to be Ba 2 Sr(VO 4)(FeO 4) instead of BaSrFeVO 6. Moreover, the symmetry should be trigonal. [ABSTRACT FROM AUTHOR]

My comments concern the significant errors in the crystallographic part of the commented paper. [ABSTRACT FROM AUTHOR]

The author of this Comment is concerned with severe errors in the crystallographic part of the commented paper. The actual composition of the crystals studied is not known, but the diffraction patterns and Rietveld analysis suggest the chemical formula of Ba 3 (VO 4) 2 :Ca. Moreover, the symmetry should be trigonal. • Several errors in the crystallographic part of the commented paper were found. • New chemical formula and crystal symmetry is proposed. [ABSTRACT FROM AUTHOR]

My comments concern the errors in the crystallographic part of the commented paper. [ABSTRACT FROM AUTHOR]

My comments concern the sever error in the crystallographic part of the commented paper. It was found that the studied crystal is of the sillenite type and the correct formula should be Bi 25 FeO 39 :Cd,Ti instead of some kind of solid solution based on BiFeO 3. Moreover, the type of unit cell is not correct. Due to the double doping the new type of unit cell, previously unknown, was proposed for such crystals. The actual chemical composition of the studied crystals is not known. [ABSTRACT FROM AUTHOR]

My comments concern the significant error in the crystallographic part of the commented paper. It was discovered that the studied crystals are of sillenite type and the correct formula should be Bi 25 FeO 39 :Ni,Ti instead of BiFeO 3. Moreover, the type of unit cell is not correct. Due to the doping the new type of unit cell, previously unknown, was proposed for such crystals. It was found that the studied sample contains two slightly different phases of the sillenite type. The actual chemical composition of the studied crystals is not known. [ABSTRACT FROM AUTHOR]

Authors say that three independent lattice parameters of the orthorhombic unit cell, a, b and c, were calculated from only one diffraction peak, i.e. using one diffraction angle and one equation 1. (http://creativecommo ns.org/licenses/by- nc- nd/4.0/) Materials Science-Poland, 38(3), 2020, pp. 400-401 http://www.materialsscience.pwr.wroc.pl/ DOI: 10.2478/msp-2018-0101 Some remarks on the paper "Optimization of S:Sn precursor molar concentration on the physical properties of spray deposited single phase Sn 2 S 3 thin films" by J. Srivind, V .S. Nagaretthinam, A.R. Balu [Mater. Some remarks on the paper "Optimization of S:Sn precursor molar concentration on the physical properties of spray deposited single phase Sn2S3 thin films" by J. Srivind, V.S. Nagaretthinam, A.R. Balu [Mater. [Extracted from the article]

For example: "peak intensity along the (1 0 0) plane" instead of correct "from the plane", "crystal orientation have changed with (...) concentration" - should be: crystallite orientation. Some remarks on the paper "Influence of zinc concentration on band gap and sub-band gap absorption on ZnO nanocrystalline thin films sol-gel grown" by Munirah, Ziaul Raza Khan, Anver Aziz, Mohd. (http://creativecommo ns.org/licenses/by- nc- nd/4.0/) MaterialsScience-Poland,38(3),2020,pp. 407-408 http://www.materialsscience.pwr.wroc.pl/ DOI:10.2478/msp-2018-0102 Some remarks on the paper "Influence of zinc concentration on band gap and sub-band gap absorption on ZnO nanocrystalline thin films sol-gel grown" by Munirah, Ziaul Raza Khan, Anver Aziz, Mohd. [Extracted from the article]

The literature data on the smallest unit cells as well as on the smallest single crystals studied by X-ray diffraction are reviewed. Different types of phase diagrams “temperature—grain size” are presented and discussed. The literature data on the grain-size driven structural phase transitions occurring in nanocrystals (quantum dots) are presented in the form of a database. It was found that there were no reports on phase transitions occurring for nanocrystalline grains with a linear dimension smaller than 7 unit cells. The grain-size driven phase transitions for some nanocrystalline double tungstates, molybdates and phosphates are also described. [ABSTRACT FROM AUTHOR]

Highlights • Several errors were found and corrected. • All corrections concern the crystallographic part of paper. • Due to the overlapping of Bragg peaks the crystallite size is not correctly calculated. Abstract The commented paper presents the results on structural and optical studies on the nanocrystals of SrAl2O4:Eu. Unfortunately, there are mistakes in the analysis of diffraction patterns in this paper which should be corrected to avoid its use in the future papers by Authors and by other people. [ABSTRACT FROM AUTHOR]

Highlights • Several errors were found and corrected. • The preferred orientation is not present in the studied samples. • Some not correct statements were explained. • Lattice parameters are given with incredible high accuracy. • All corrections concern the crystallographic part of paper. [ABSTRACT FROM AUTHOR]

Highlights • Several errors were found and corrected. • Some not correct statements were explained. • All corrections concerns the crystallographic part of paper. [ABSTRACT FROM AUTHOR]

The correct values of crystallites size of Y 2 SiO 5 powder are presented as a correction of data published in the commented paper. Additionally, the description of the size-induced phase transition is given. • The size-induced phase transtion is discovered. • The correct values of crystallite sizes have been presented. • The correction of errors in the previously published paper is presented. [ABSTRACT FROM AUTHOR]

Abstract: Well-crystallized MnWO4 nanoparticles with 20–100nm sizes were synthesized by a mild hydrothermal crystallization process. X-ray diffraction and TEM results show that particles have tendency to grow in a shape of nanorods elongated in the c direction. They also show that the particles synthesized from MnCl2 have smaller concentration of defects than those synthesized from MnSO4·H2O. Raman spectra revealed weak changes with decreasing particle size due to phonon confinement effect and defects. In contrast to this behavior, IR spectra showed much more pronounced changes. Origin of this behavior is discussed. Raman and IR spectra showed also presence of additional bands at 923 and 914cm−1, respectively. These bands have been attributed to presence of terminal Wt the surface of MnWO4 nanocrystallites. Specific heat and magnetization studies revealed broad anomalies at 11.0–11.4K, which correspond to the two magnetic transitions found for bulk MnWO4 at 12.5 and 13.5K. [Copyright &y& Elsevier]