Q. Which of the following is/are examples of van der Waals materials?
1. Graphite
2. Antimony
3. Selenium
Select the correct answer using the codes given below:

[A] 1 only

[B] 1 and 2 only

[C] 2 and 3 only

[D] 1, 2 and 3

Answer: D
Notes:

Until six years ago, such materials did not exist but today, researchers believe that they hold the key to‘post-silicon’ electronics.  

  • VdW materials are made of piles of ultra-thin layers that are held together by weak van der Waals bonds, which arise when atoms are in close proximity.  
  • The success of graphene — a well known vdW material — stimulated scientists to look for other 2D crystals, where layers can be changed, added or removed in order to introduce new physical properties such as magnetism.  
  • Controlling magnetism, as is typical of such materials, could replace the current hard drive assemblies in computers and even become the key to quantum computing. 
  • Other examples of natural elemental van der Waals materials, although much less abundant than graphite, are native bismuth, antimony, selenium, and tellurium. 

Source: The Hindu and Nature publications