public static Geodatabase CreateGeodatabase( 
   MemoryConnectionProperties memoryConnectionProperties
)

// Create the memory connection properties to connect to  default memory geodatabase
MemoryConnectionProperties memoryConnectionProperties = new MemoryConnectionProperties();

// Alternatively create the memory connection properties to connect to memory geodatabase named as 'InterimMemoryGeodatabase'
// MemoryConnectionProperties memoryConnectionProperties = new MemoryConnectionProperties("InterimMemoryGeodatabase");

// Create and use the memory geodatabase
using (Geodatabase geodatabase = SchemaBuilder.CreateGeodatabase(memoryConnectionProperties))
{
  // Create additional schema here
}