Rare Earths-H systems : basic knowledge

This page under construction is dedicated to :

Rare Earths-H systems (R-H systems) with R = Sc, Y and the 15 Lanthanides.

For the moment, the only present matter (below) is that brought to our attention by Peter Vajda* -- suggestion made in the framework of our recent MH-2024 Poster calling for help from long-experienced Hydriders :).

*Laboratoire des Solides Irradiés, Ecole Polytechnique, CNRS/CEA, Palaiseau, France.
We warmly acknowledge Prof. Vajda for the suggestion of the two Chapters (1.a.1 + 1.a.2) -- where the former Chapter was sent to us in the form of a floppy disk :). We have also added Peter's last book (1.b) since it includes matter related to Rare Earths-H systems, along with some updates of the said two Chapters.

Table of Content

To find a given item :
just use CTRL + F on your keyboard

1) General Material

1.a) Peter Vajda's reviews

   1.a.1) Vajda's 1995 chapter in the "Handbook on the physics and chemistry of rare earths, Vol. 20"

   1.a.2) Vajda's 1996 chapter in the "Hydrogen metal systems, I" book

   1.a.3) Vajda's 2013 updates of 1.a.1 and 1.a.2

1.b) Peter Vajda's recent book (Properties of fluorite structure materials) with updates for 1.a.1 and 1.a.2
N.B. : all papers / chapters / books mentioned in this page can be downloaded via LibGen or Sci Hub
(except : those directly downloadable thanks to the blue/black boxes, or a few exceptions).
Via Sci-Hub : just enter the DOI number, bingo !
Via Libgen : just enter the keys words, bingo !
1) General Material
1.a) Peter Vajda's reviews
   1.a.1) Vajda's 1995 chapter in the "Handbook on the physics and chemistry of rare earths, Vol. 20"
Chapter's title : Hydrogen in rare-earth metals, including RH2+x phases*.
*This review is dedicated to the memory of J.N. Daou, a pioneer of the rare-earth hydrides.
Chapter's details : n° 137, pp. 207-291, with 85 pages.
by : Peter Vajda.
in : Handbook on the physics and chemistry of rare earths, Vol. 20, 1995, edited by Karl A. Gschneidner, Jr. and LeRoy Eyring.
Table of Content (from the publisher, as a 1st page preview)

How to find this Chapter :
DOI :  10.1016/S0168-1273(05)80071-6

Note that the said Volume 20 can be found in LibGen.

For your information :

-All the other Chapters within this Handbook (Vol. 20) can be found here : https://www.sciencedirect.com/handbook/handbook-on-the-physics-and-chemistry-of-rare-earths/vol/20/s....

-The other Volumes can be consulted here : https://www.sciencedirect.com/handbook/handbook-on-the-physics-and-chemistry-of-rare-earths.

Personal note :

see emails with Peter in the folder : MH-2024/POSTERS/Le Notre/Retours/Peter Vajda.


1.a.2) Vajda's 1996 chapter in the "Hydrogen metal systems, I" book
Chapter's title : Rare Earths-Hydrogen.
Chapter's details : n° 4, pp. 71-157, with 87 pages.
by : Peter Vajda and J.N. Daou.
in : the book "Hydrogen Metal Systems I" (editors, F.A. Lewis and A. Aladjem, 1996) published in "Solid State Phenomena" Vol. 49-50, 1996.
Table of Content (from the publisher, as a 1st page preview)
How to find this Chapter :
DOI : 10.4028/www.scientific.net/SSP.49-50.71.

For your information :

-All the other chapters included within the book "Hydrogen Metal System I" can be found here : https://www.scientific.net/SSP.49-50.

-The other related book "Hydrogen Metal System II" can be found here : https://www.scientific.net/SSP.73-75.

Personal note :

see emails with Peter in 2017 in the folder : Science info/Scientists/H in Metals/P. Vajda.


1.a.3) Vajda's 2013 updates of 1.a.1 and 1.a.2

Note that Peter Vajda* made an update of the two above chapters, in 2013, in the chapter "Rare earth (and actinide) dihydrides: structural, electronic and magnetic properties" in the book "Properties of fluorite structure materials". See just below in the section 1.b.
*personal communications with Peter (email dated Dec. 04th, 2017, in the folder Science info/Scientists/H in Metals/P. Vajda).

1.b) Peter Vajda's recent book (Properties of fluorite structure materials) with updates for 1.a.1 and 1.a.2
Picture from the publisher (Nova Science)


The present work focuses on two fluorite-structured groups of materials: 

the hydrides of the rare earths (and actinides) and several specific metal oxides, and is authored by researchers among the most competent and active in the field. 

By contrast to the classical “historic” alkaline-earth halides, non-stoichiometry appears as a key issue for both groups treated here. 

The former group has attracted particularly close attention because of its possible candidature as hydrogen storage material within the vast prospect of the clean energy economy.

In the second group, a chapter is devoted to the (antifluorite-type) lithium oxide, a candidate for (super)ionic batteries (again interesting for the clean energy technology) and as a tritium “breeder” in fusion reactor walls. Finally, two more chapters are dedicated to the radiation effects on actinide dioxides (like uranium dioxide), and yttria-stabilized zirconium dioxide which is envisioned as an inert confinement matrix for actinide transmutation in nuclear reactors.

picture from our own hardcover copy
picture from our own hardcover copy
Book's title : Properties of fluorite structure materials.
Editors : Peter Vajda and Jean-Marc Costantini.
Publisher : Nova Science.
Year : 2013.
Pages : 195.

Book reviews :
(i) by Dr. Clark S. Snow :
  • Calcium fluoride, CaF2, occurs naturally as the mineral fluorite which lends its name to the deceptively simple cubic structure of four FCC Ca atoms and eight tetrahedrally coordinated F atoms. In simplicity
  • often lies rich diversity, this is certainly the case with materials with the fluorite structure. The book “Properties of Fluorite Structure Materials” Edited by Peter Vajda and Jean-Marc Costantini demonstrates how such diversity in fluorite materials arrives from small changes in stoichiometry.
  • “Properties of Fluorite Structure Materials” Edited by Peter Vajda and Jean-Marc Costantini covers a wide range of research based solely on those materials with the fluorite structure. A common theme running through the book is the impact of non-stoichiometry on the diverse range of properties. In fact, an appropriate sub-title or alternate title could be “The impact of non-stoichiometry on the properties of fluorite materials.” This book can be considered a follow on to “Crystals with the Fluorite Structure” edited by W. Hayes and published in 1974. The book by Hayes focused mainly on point defects in fluorite structure materials while the current book emphasizes non-stoichometry.
  • The book contains six chapters covering the rare-earth (and actinide) di-hydrides and irradiation induced properties in lithium oxide, cubic-stabilized Zirconium and Ceria, and actinide compounds. If the book was longer it could be divided into two parts, the metal hydrides and radiation induced damage. The importance of non-stochiometry in the metal hydrides is demonstrated with first-principles calculations and experiments revealing changes in their electronic and magnetic properties as a function of hydride stoichiometry. Similarly, changes in stoichiometry induced by radiation damage are manifested in changes to the properties of LiO2, ZrO2-x and CerO2-x, and a variety of actinide compounds. Non-stoichiometry, whether induced via an outside force or intentionally introduced, seems to have a drastic and interesting impact on the properties of fluorite materials.
  • Each chapter is of appropriate length and technical depth to provide an excellent review of the topic. A researcher in these areas would be well served to use these chapters as a starting point for further study. However, a book must be judged not only on its written content but also on its presentation. While the content of the book is excellent, the presentation in some chapters is lacking. My greatest complaint is in the quality of the figures in some chapters, especially those figures in Chapters 2 and 3. The figures are blurry and appear to be scanned copies rather than originals. It is unfortunate because these figures detract from an excellent technical book.
  • While no human product is perfect this book serves as a valuable contribution to the scientific literature. Each chapter stands alone as a solid introduction to that particular field. Who knew such a simple crystal structure could yield such fascinating science.
Dr. Clark S. Snow
Principal Member of the Technical Staff
Sandia National Laboratories
Albuquerque, NM

(ii) by Prof. Klaus Yvon :
  • There are not many books dedicated to materials properties of a specific crystal structure type. “Properties of Fluorite Structure Materials” (195 pages), edited by Peter Vajda and Jean-­‐Marc Costantini, is one of them.
  • Interestingly, the Editors chose to treat only two classes of fluorite type compounds, i.e. hydrides (rare-­‐earth, actinides) and oxides (lithium, zirconium, cerium, actinides), and both have very different properties (mainly metallic and magnetic for the hydrides, non-­‐metallic and mainly non-­‐magnetic for the oxides). While this approach precludes comprehensiveness, it has the advantage of conveying to the reader a well-­‐focused view on recent advances in two important subfields of the energy sector, i.e. hydrogen technology on the one hand, and solid oxide fuel cells and nuclear reactors on the other.
  • Specifically, the book focuses on first-­‐principles calculations for rare earth hydrides and the influence of compositional changes on their electronic and magnetic properties, including high-­‐pressure effects, and on the influence of irradiation on properties, such as the creation of point defects (lithium oxide), lattice damage (zirconia, ceria) and radiation damage built-­‐up in nuclear fuels (actinide oxides). As the reader will discover by himself, a common feature of the materials treated in the book is the big influence of small deviations from CaF2 stoichiometry and crystal structure on their properties.
  • The book is grouped into six chapters, which are treated by world-­‐leading experts in the fields. Their texts are clearly written, and the illustrations figures, diagrams, charts and tables are abundant, although the quality of the figures reproduced in some chapters leaves to be desired.
  • A particularly welcome addition at the end of the book is the subject Index, which goes to the merit of the Publisher. Although some subjects treated in the text do not appear in this Index, such as the element names Praseodymium, Samarium, Erbium, Gadolinium, Terbium, Dysprosium, Thulium, its overall usefulness is obvious.
  • This book (edition 2013) is an invaluable resource for materials scientists and solid-­‐state physicists and chemists with an interest in hydrides and oxides in the energy sector, as well as for advanced students and graduates who wish to familiarize themselves with these important classes of compounds. As to the latter audience, one might regret the book’s relatively high price, given that free access is granted only to one of the chapters. 
  • Notwithstanding this, you cannot go wrong with this book. From the physics and chemistry graduate to the experienced material scientist, this is a great reference. Anyone not already a material’s buff in the energy sector will learn a lot.
Klaus Yvon, Professor
Physics Department
University of Geneva.
Text taken from : https://novapublishers.com/wp-content/uploads/2019/05/Book-Review-Properties-of-Fluorite-Structure-M....

How to find this book :
(i) from the publisher : https://novapublishers.com/shop/properties-of-fluorite-structure-materials/.
(ii) from LibGen : not yet available.

Personal note :
see emails with Peter in 2017 + 2024 in the folder [Science info/Scientists/H in Metals/P. Vajda] and [Science info/Soc. scien & Conf/H/Conf/MH...=ISMHS/ISMHS 2024 France].

Acknowledgements are due to Peter Vajda for a hardcopy sent to us in Feb. 2024. Thank you Peter !