HAFNIUM FLUORIDE Chemical Properties

Melting point:

310°C (subl.)

Boiling point:

970°C

Density 

7.100

solubility 

reacts with H2O

form 

Powder

color 

White

Water Solubility 

React with water.

Sensitive 

Moisture Sensitive

Exposure limits

ACGIH: TWA 2.5 mg/m3; TWA 0.5 mg/m3
NIOSH: IDLH 250 mg/m3; IDLH 50 mg/m3; TWA 0.5 mg/m3

CAS DataBase Reference

13709-52-9(CAS DataBase Reference)

Safety Information

Hazard Codes 

Xi,T

Risk Statements 

32-36/37/38-41-23-37/38

Safety Statements 

26-36-45-36/37/39

RIDADR 

UN 2923 8/PG 2

WGK Germany 

3

Hazard Note 

Irritant

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

II

HS Code 

28261990

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ALFA

HAFNIUM FLUORIDE Usage And Synthesis

Preparation

Hafnium tetrafluoride may be prepared by passing anhydrous hydrogen fluoride over hafnium tetrachloride at 300°C:
HfCl4 + 4HF HfF4 + HCl
Another method of preparation involves thermal decomposition of ammonium fluorohafnate, (NH4)2 HfF6 [16925-24-9] in the absence of air:
(NH4)2 HfF6 HfF4 + 2NH3 + 2HF
Also, HfF4 can be prepared by treating metallic hafnium with 40% aqueous HF. The monohydrate formed may be heated at 350°C for several days under a flow of fluorine and nitrogen to yield anhydrous HfF4.
Hf + 4HF (aq) → HfF4•H2O + 2H2

Chemical Properties

Off-white powder

Physical properties

White monoclinic crystals; refractive index 1.56; density 7.1 g/cm³; sublimes at 970°C.

Uses

Hafnium(IV) fluoride is used as Vacuum deposition.

Production Methods

Hafnium tetrafluoride is prepared by careful thermal decomposition of ammonium fluorohafniate in an oxygen- free atmosphere or by passing anhydrous hydrogen fluoride over hafnium tetrachloride at 300℃. Direct synthesis from the elements is incomplete because the product merely forms a film on the metal. Ammonium fluorohafniate can be prepared by crystallization from an aqueous hydrofluoric acid solution by adding ammonium fluoride.

HAFNIUM FLUORIDE(13709-52-9)Related Product Information

• HAFNIUM FLUORIDE
• HAFNIUM HYDRIDE
• HAFNIUM