X-ray diffraction study of the p-T phase diagram of crystalline and disordered gallium antimonide

Journal Article · Tue Nov 01 04:00:00 EST 1994 · Inorganic Materials

OSTI ID:75669

Malyushitskaya, Z V ^[1]

---

1. Vereshchagin Institute of High-Pressure Physics, Moscow (Russian Federation)

The semiconductors Si, Ge, and GaSb have similar energy-band structures under normal conditions and become electronic analogs at p {ge} 3.0 GPa. The structural changes in GaSb under pressure have much in common with those in Si and Ge. The semiconductor-to-metal transition in GaSb is accompanied by a resistivity jump and transformation of the ambient-pressure sphalerite structure (I) to the {beta}-Sn structure (II) with a volume increase of 16.9%. As evidenced by X-ray diffraction, the I {yields} II transformation occurs at 6.2 {+-} 0.3 GPa. More recent X-ray diffraction studies of GaSb at 298 K over a wider pressure range, up to 110 GPa, have demonstrated that the analogy with Si and Ge holds at still higher pressures. At 27.8 GPa, GaSb undergoes a transformation into a phase with a simple hexagonal structure, whereas above 61.0 GPa this phase is replaced by an unidentified disordered phase (presumably, orthorhombic), which persists up to 110 GPa. The high-pressure {beta}-Sn phase of GaSb can exist, as well, at 90 K and ambient pressure, but, when warmed up, it transforms into a metastable amorphous modification whose X-ray diffraction pattern shows two diffuse halos at 3.5 and 1.9 {angstrom}. A similar disordered phase of I-GaSb can be obtained from II-GaSb at room temperature by rapidly reducing pressure from p = 12 GPa. Upon heating to 470 K over a period of 1 h, the amorphous phase transforms into a crystalline one. The conditions for solid-state amorphization of GaSb and nearly equiatomic Ga-Sb alloys quenched after exposure to p = 9 GPa and T = 420-570 K were studied. The purpose of this work was to obtain systematic data on the high-pressure behavior of the tetrahedral semiconductors by studying crystalline and structurally disordered (obtained by liquid quenching under pressure) samples of GaSb using X-ray diffraction at pressures 0-12 GPa and temperatures up to 673 K.

• OSTI ID: 75669
• Journal Information: Inorganic Materials, Journal Name: Inorganic Materials Journal Issue: 11 Vol. 30; ISSN INOMAF; ISSN 0020-1685
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM ANTIMONIDES
HIGH PRESSURE
LOW PRESSURE
MEDIUM PRESSURE
PHASE DIAGRAMS
PHASE STUDIES
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
VERY HIGH PRESSURE
X-RAY DIFFRACTION