Iron vanadium tetraoxide

Melting point / freezing point

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

melting point/freezing point

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

purity, expiry date, batch number, accuracy of the method were not stated

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 102 (Melting point / Melting Range)

Deviations:

yes

Remarks:

purity, expiry date, batch number, accuracy of the method were not stated

GLP compliance:

not specified

Type of method:

other: TGA and DSC

Melting / freezing pt.:

> 700 °C

Decomposition:

no

Sublimation:

no

Thermal stability was analysed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) curves.

In an air atmosphere the TGA trace shows a 0.4 wt % weight loss between room temperature and 700 °C which is due to the desorption of water and absorbed gases. The DSC trace shows no phase transitions or sample decomposition. These both suggest that FeVO₄ is thermally stable in air within the measured temperature range.

In 5 % H₂/Ar the TGA Trace shows no significant weight loss up to 550 °C, at which weight loss begins to occur. This corresponds which sharp increase in heat flow on the DSC trace suggesting that the weight loss is exothermic. The total weight loss after reduction is approximately 12 wt % and is likely to be due to the loss of oxygen from compound decomposition.

Conclusions:

FeVO4 is thermally stable in air within the measured temperature range from room temperature up to 700 °C.

Reference 2

Endpoint:

melting point/freezing point

Type of information:

other: secondary source

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Qualifier:

no guideline followed

Principles of method if other than guideline:

In the publication "Reactivity of FeVO4 towards Mg2V2O7 and phase relations in the FeVO4-Mg2V2O7 system up to the solidus line, Bolonska-Tabero, A. and Kurzawa, M. (2005), Ceramics-Silikáty 49 (2), pp.132-137" the information "Iron (III) orthovanadate(V) melts incongruently at 850 °C with a separation of solid α-Fe2O3" from the publication "Walczak, J. et al., Polish J.Chem. (1985) 59, p. 255" was stated.

GLP compliance:

not specified

Type of method:

other: no data

Decomposition:

yes

Decomp. temp.:

850 °C

Sublimation:

no

Iron (III) orthovanadate(V) melts incongruently at 850 °C with a separation of solid α-Fe₂O₃.

Conclusions:

Iron (III) orthovanadate(V) melts incongruently at 850 °C with a separation of solid α-Fe2O3.

Description of key information

Iron vanadium tetraoxide is thermally stable in air up to 700 °C (Cowing, 2011). According to Blonska-Tabero (2005), iron vanadium tetraoxide melts incongruently at 850 °C with a separation of solid α-Fe₂O₃.

Key value for chemical safety assessment

Melting / freezing point at 101 325 Pa:

850 °C