Comment on “Lattice deformation and magnetic properties in epitaxial thin films of $Sr1−xBaxRuO3$” [Appl. Phys. Lett. 73, 1200 (1998)]

N.

Fukushima

,

K.

Sano

,

T.

Schimiza

,

K.

Abe

, and

S.

Komatsu

, , ().

M. K. Lee, I. W. Scrymgeour, J. Lettieri, D. G. Schlom, and C. B. Eom (unpublished).

J. M.

Longo

and

A. J.

Kafalas

, , (). The lattice constants of the metastable perovskite polymorph of $BaRuO3$ (pseudocubic with $a≈4.01 Å$⁠) have been estimated by extrapolating the lattice constants reported in this work for $BaxSr1−xRuO3$ to $x=1.$

Powder Diffraction File (International Centre for Diffraction Data, Swarthmore, PA, 1995), JCPDS card 45–529. This reference states that the $9L$ polymorph of $BaRuO3$ has lattice constants $a=5.749 Å$ and $c=21.608 Å.$

J.

Lettieri

,

C. I.

Weber

, and

D. G.

Schlom

, , ().

S.-W.

Chan

, , ().

Our films showed evidence of a mixture of both the four layer $(4L)$ and $9L$ hexagonal polymorphs. Discrimination of the $4L$ polymorph from the perovskite phase is equally as difficult since the $202̄3,$ $112̄0,$ and $224̄0$ reflections of the $4L$ structure also exhibit a near overlap of peak position and intensity with the perovskite polymorph (and with the $202̄5,$ $112̄0,$ and $224̄0$ reflections of the $9L$ polymorph). A φ scan of the $011̄5$ reflection of the $9L$ polymorph or the $011̄2$ reflection of the $4L$ polymorph is sufficient to distinguish between these two phases. Nevertheless, in none of our films grown under a wide range of growth conditions by both sputtering and pulsed laser deposition was the perovskite polymorph evident.

H.-M.

Christen

,

L. A.

Boatner

,

J. D.

Budai

,

M. F.

Chisholm

,

L. A.

Gea

,

D. P.

Norton

,

C.

Gerber

, and

M.

Urbanik

, , ().